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This is a partial character sheet for Kamen Rider Build. Visit here for the main character index. Subjective trope and audience reactions should go on the YMMV page.

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Kamen Riders

    Sento Kiryu/Kamen Rider Build 

Sento Kiryu/Kamen Rider Build

Portrayed by: Atsuhiro Inukai (live), Seiji Takaiwa (suit)
"I've found the winning formula!"

The main protagonist, Sento is a self-proclaimed handsome and brilliant theoretical physicist suffering from amnesia that made him forget the last 20 years of his life. He transforms into Kamen Rider Build in order to fight the Smash and learn the truth about himself. His genius mind enables him to create Build and Cross-Z's equipment.

His actual identity is the "Devil's Scientist" Takumi Katsuragi, who had his face swapped with that of the guitarist Taro Satou, who was killed in place of him one year ago. After the face swap, Soichi Isurugi removed Katsuragi's memories and placed him under Faust's Nebula Gas experimentation. Then, Soichi took him and provided Sento with the Build Driver so that he could manipulate him into completing his own work.

Tropes that apply to him in general

  • Amnesiac Dissonance: Acknowledging it is part of Sento overcoming his Heroic BSoD in #16. Neither the person whose face he's taken nor the person he was before would have become a hero, even if given the chance: only Sento Kiryu did.
    • Late in the series, it's implied that Sento is very similar to what Takumi Katsuragi was like before the Sky Wall Incident, based on how he acts both in flashbacks to that period and how he remains unchanged even after having his memories up to the Sky Wall incident restored. Takumi, however, has been shaped by the ten years after the Sky Walls into a much different person.
  • Amnesiac Hero: He has no memories prior to his escape from the lab where he was experimented upon. This is because Soichi removed it. It was revealed that Nebula Gas experimentation only alters memories for several hours.
  • All-Loving Hero: His ego is only eclipsed by his drive to help others and preserve life.
  • Anti-Hero: Implied: His premiere appearance in Kamen Rider Ex-Aid, had him show up to take a sample of Emu's essence and then, in contrast to how new and old Main Characters would briefly team-up during the finale of the current series, leaving the heroes to deal with the pandemic themselves. This event occurred before his memory loss, back when he was the much less scrupulous Takumi Katsuragi, who is far more anti-heroic than his current personality as Sento.
  • Animal Motifs: While most of Sento’s forms as Build involve a different animal, examples being Hawk/Gatling or Rocket/Panda, the biggest and most prominent one is rabbits. His base form is Rabbit/Tank, his hair tends to flip up like a Rabbit’s ear when he’s excited or scratches his head, his first major powerup and penultimate form and even final forms involve Rabbits.
  • Badass Bookworm: Sento is proficient with firearms, can ride his bike at high speeds, and has decent hand-to-hand fighting skills even when he isn't Build.
  • Bash Brothers: Sento and Ryuga show shades of this in his pre-Rider days, with them falling into this kind of relationship once he becomes Cross-Z. Most of their conversations between battles consist of throwing shade at each other, approaching a full-fledged Boke and Tsukkomi Routine, but they come together the moment a threat arises. Once Kazumi changes to their side, there is a brief period where it seemed he and Sento would form a pair over Ryuga and Sento, but with the arrival of Cross-Z Magma and Rogue's turn to good, Sento and Ryuga quickly re-established themselves as the alpha pairing. They have the best sync in fights and their much higher power levels means they are the combat team to Grease and Rogue's support.
  • Berserk Button: Calling cruel weapons like the Transteam Gun's Devil Steam as "inventions" is a quick way to draw Sento's ire. Taunting him with the secrets of his past is a much faster way, at least before he knew.
    • Don't hurt his family. He will think up some creative way to strike back and no one is going to like it.
  • Big Ego, Hidden Depths: Its surprisingly easy to look beneath underneath Sento's narcissism and discover a man completely at a lost of just what his place in the world is but none the less tries to be the best human being he can possibly be.
  • Catchphrase: His pre-battle catchphrase is "Now, shall we begin the experiment?" This came up when he first tried transforming to Build, as he didn't know what he was doing, at all, so it was a thing that just stuck.
    • When things are going his way, he says "This is the best!"; by contrast, when they don't he says "This is the worst!". He tends to say one or the other at least Once an Episode.
    • He also tends to say "hang on" or "wait a second" before following up with an attack.
    • When he turns into Build he uses "The law of victory has been decided!"note ; alternate translations include "I've found the formula of victory!", "I've found the winning formula!", and "Victory conditions have been cleared!"note 
    • He uses "Build up!" when changing forms.
    • He had "the handsome and brilliant physicist Sento Kiryu!" to refer to himself every time during recap. He drops it after the war situation become more severe.
    • A minor example, his victorious genius routine: "Ain't I great? Ain't I awesome? Ain't I a genius?" every time he admired his own work and "How do you like, my in-ven-tion?" when he bragged about his invention to others.
  • Character Tics: As noted by his father, Sento makes the habit of messing with his hair whenever he is anxious, upset, or excited.
  • Chronic Hero Syndrome: Sento just can’t let anyone suffer if he can stop it. No matter what, he will attempt to save whoever he comes across.
  • Contrasting Sequel Protagonist: Sento is obviously more acerbic than his predecessor Emu Hojo, and where Emu was a poorly-respected member of a well-respected profession, with the backing of the Japanese government, Sento is well-respected by his peers but a criminal in the government's eyes. Despite the points of contrast, though, both are equally driven by the basic desire to help people, and prioritize the health of others over their own needs. In an unusual case, Sento can also apply the contrast to Ex-Aid's Deuteragonist Kuroto Dan, as both have an Insufferable Genius nature and created their own belts and weaponry, with the difference being that Sento is genuinely heroic where Kuroto is a Heroic Comedic Sociopath at the best of times.
  • Cutting the Knot: Sento seems to favor the no-nonsense solution whenever the option is available. An early example involves him taking a hammer to his own basement wall as soon as the evidence suggests that this is a good idea.
  • Darkest Hour: Sento's occurs not during the series, but in Be The One. He's been completely isolated by the Blood Race, who brainwashed all of Japan (including Banjo, Misora, and Sawa) into hating Build, and captured Kazumi and Gentoku since they can't be brainwashed. After being defeated by Banjo, the Big Bad Kengo Ino rips open the old wound of Build being a "fake hero", and even his faith in science seems to have failed him. After angsting for a while and debating the Takumi personality, Sento declares that even if the world hates him and everything he believed in was fake, there are still some undeniable truths: his bond with Banjo, and his father's belief in Love and Peace, which gives him the resolve to keep fighting and save the world.
  • Deadpan Snarker: Has got snark and sarcasm for days.
  • Determinator: Just like Ryuga. Sento is made of iron, justice and occasional suicidal tendecies, so when he sets his mind on something, not even the end of the world is enough to stop him.
  • Did You Just Flip Off Cthulhu?: He constantly delays Evolto's plans. As of #41, Evolto is so angry he promises that he won't kill Sento before crushing everything he has down to the last hope.
  • Dissonant Serenity: He can keep calm, detached attitude on deeply unsettling occasions like the revelation of his identity or war breaking out pretty much in his backyard. It's apparently his defense mechanism to keep himself focused on the task at hand without getting distracted by his emotions. It usually works only until he is called out on it or more things are heaped on him.
  • Driven to Suicide: Sento attempts to commit suicide by self-destruct switch in #22, traumatized by the monster the Hazard Trigger turns him into. Misora calls him out on both the suicide attempt and forcing her to be the one to push the button, and thanks to Sawa and Ryuga, he doesn't go through with it.
  • Dull Surprise: His reaction to things that don't concern him, someone (like Ryuga) doing something stupid and most of the overall silliness inherent to his team.
  • Empty Shell: Sento's first use of the Hazard Trigger leaves him so horrified by what he proceeds to do under its influence that he's left a depressed wreck. To accentuate this point, in #21, most times when his face is shown, his eyes are framed in such a way that they look completely black.
  • Family of Choice: He eventually comes to think of the entire nascita gang as his true family.
  • Fashionable Asymmetry: Not as apparent as his Rider form, but he wears two different colored sneakers - one red, the other blue.
  • For Great Justice: His motivatining mantra is that he fights for “love and peace”.
  • For Science!: Sento believes that science is neither "good" nor "evil"; like any other tool, it all comes down to how it's used. That said, he considers some inventions like the Sclash Driver and Hazard Trigger too dangerous to ever use.
  • Genius Bruiser: Sento is a physicist and the most intelligent of the Heisei Riders, while being as combat-capable as all the other Riders are. Thanks to his elevated Hazard Level, his physical abilities are mildly superhuman even when not transformed.
  • Good Feels Good: He enjoys the feeling of helping people, and notes that it always puts a smile on his face to save someone from, or from being a Smash.
    "It puts a smile to my face, you know. Helping people. Not that you can see with the mask on."
  • Guile Hero: When the situation calls for it, he has shown to have the capability of properly pulling off a Batman Gambit, even managing to Out Gambit Evolto on more than one occasion. Most prominently at the end of the series.
  • Heroic BSoD: When Sento encounters a source of emotional distress too great to deflect, he tends to shut down entirely. #16 and #21 feature prominent examples.
  • Heroic Willpower: Manages to resist Tid's mind control in Heisei Generations Forever.
  • He's Back!: Pulls this off twice through-out the entire series, once in #16 after a pep-talk from Banjo. Of note especially is when he regains his memories of being Sento Kiryu after having reverted to being Takumi Katsuragi, which he follows up on by transforming into Build Genius Form for the first time.
  • Hot Scientist: Has the habit of calling himself "the brilliant and handsome genius" and Atsuhiro Inukai is most certainly not bad on the eyes.
  • Idiot Hair: Often happens when he does something silly, gets ahead of himself or gets an idea, though it appears from the side of his head instead of up top. Taro Satou had all of his hair like this.
  • Insufferable Genius: He loves bragging about his inventions whenever he gets the chance, but is still a lot more amiable most of the time than expected from this trope.
    Opening narration: "The handsome and brilliant physicist Sento Kiryu!"
    After finishing something: "Ain't I great? Ain't I awesome? Ain't I a genius?"
  • Irony: For all of his claims of love and peace at the end of the day Sento is the one person that is unwilling to move on from his life as a Kamen Rider. His new lab is a near exact replica of the Nascita basement. He still stupidly keeps the white panel around instead of destroying it, The Killbus spider is essentially Ryuga's morpher but better sold as a children's toy, and when Gentoku and Kazumi came knocking he was quick to restore their powers.
  • Jerk with a Heart of Gold: Narcissistic tendencies aside, deep down, Sento is a pretty caring person.
  • Laser-Guided Amnesia: He can't remember much about 20 years of his past, save for that he was experimented on by Night Rogue.
  • Like Brother and Sister: He forms this sort of bond with both Banjo and Misora. Banjo eventually becomes a brother to be trusted with his life while Misora is the little sister to be teased and protected.
  • Manchild: A downplayed example. Sento is usually the responsible one to Ryuga, but there are moments when he acts like a child (petulant or other). Also, there are hints of Psychopathic Manchild turning up at the rare occasion he jokingly threatens someone with his newest weapon after building it.
  • Meaningful Name: Sento's name is composed of the first kanji for tank (戦車 Sensha) and the kanji for rabbit (兎 To). Knowing the person who gave it, Soichi most likely gave it with the meaning intended. Confirmed in the recap segment at the start of #9, where Ryuga raises the point, Soichi explains the name and Sento incredulously shouts, "So you just named me RabbitTank?!"
    • Averted with his surname, Soichi just took it from his favorite barber shop. There is still some significance to it as it's second kanji is for life (生 ikiru), matching Sento's Thou Shalt Not Kill attitude and Katsuragi's new life as Sento.
    • It also applies to Taro's name, only not quite as literal: his first name is based on the EH500 Kintaro Tank freight train, and his last name is the same with the protagonist of a Japanese children picture book, Sato-kun the Rabbit.
  • Neat Freak: By his own admission, he is this. Which completely shocks him when he sees 'his' former identity's room.
  • Nice Job Breaking It, Hero: On at least two occasions.
    • The first is him completing Kasturagi's development of the Sclash Driver, which by the way exposes the user to the full effects of the Nebula Gas, making them more violent with prolonged usage unless they somehow overpower its effects. This leads to the birth of Kamen Rider Grease and Rogue, the latter of which was by far one of Sento's more dangerous foes until Evolto got his hands on his own belt. To be fair to Sento, Blood Stalk and Gentoku tricked Sento into completing it since he had no idea about the belt's nasty side-effects.
    • The second time Sento screwed up, again for reasons he couldn't have known otherwise, is arguably much worse. His decision to keep the White Panel of the Pandora's Box instead of destroying it gave Killbus free entry into the new world.
  • Not Worth Killing: After they steal all the Fullbottles he had on his person at the end of #10, Night Rogue and Blood Stalk opt to leave him wounded in the dirt instead of finishing him off. They still need him to purify the remaining Fullbottles and finish the Sclash Driver, after all.
  • Perpetual Frowner: The events from #17 onward put Sento through a long period of being unable to smile. It's not until ten episodes later that things finally begin to look up for him.
    Ryuga: He doesn't smile anymore, you know?
  • Phlebotinum Rebel: Was one of the individuals who were captured and experimented by Faust, or rather, his current personality was created by Evolto to do his dirty work behind his back before he starts to opposed him for good. He was also the captor and experimenter himself before this happened.
  • Quest for Identity: Knee deep in it, still nowhere near getting to know who he really is and each turn provokes more questions then it gives answers. A Red Herring is floated before #15 finally reveals his true identity: Takumi Katsuragi, the Devil's Scientist himself. It isn’t until the mid point of the series that he declares that his current personality is enough of an identity on its own.
  • Red Oni, Blue Oni: The blue to Banjo's red. Not only is Sento the intellectual of the two, the Tank Halfbody's color is blue.
  • Science Hero: He's a physicist who happens to be a Kamen Rider. He even makes his own gear!
  • Say My Name : EVOLTOOO!!! Evolto sauntering on the scene as if nothing happened despite being in the middle of The End of the World as We Know It that he caused was just too much.
  • Silly Rabbit, Cynicism Is for Losers!: When others denounce his “love and peace” mantra as overly simplicity and childish, he responds with this. He knows that it’s unrealistic and will lead to heartache for himself, but still says that it’s more than enough of a goal for him to never stop fighting for.
  • Stepford Smiler: Like his pre-amnesiac self, Sento's default response to emotions he doesn't feel comfortable expressing is to deny they exist. It works if the problem he's dealing with isn't too big, but the strategy fails him more and more as his situation worsens.
  • Talking to Themself: He occasionally converses with his original self in a mindscape with doors, equations and gears after regaining his memories and becoming the identity in control. It goes as well as a conversation between a staunch cynic and optimist can.
  • Think Nothing of It: As he explains to Ryuga, he doesn't consider helping people to be justice if you expect a reward for doing it.
  • Thou Shalt Not Kill: He has a strict policy against killing his opponents or letting innocent bystanders die. Which is partially why the revelation that he was Katsuragi, a scientist who performed lethal experiments on human test subjects dozens of times hurts him rather badly, and what he does under the influence of the Hazard Trigger breaks him outright.
  • Trauma-Induced Amnesia: It is safe to say that the cause of his amnesia is all the experimentation done on him by Faust's scientists.
    • Or so he is led to believe. Then in #15, it was revealed that this is because Soichi removed his memories. The experimentation only altered his memories of several hours.
  • Unwitting Pawn: Most of Sento's actions prior to #14 are playing into Faust's hands. Even afterward, he quite willingly finishes designing the Sclash Driver, allowing Blood Stalk to steal its data and give one to Hokuto. It isn’t until late in the series that he finally slips all outside control and completely turns the tables on his manipulators.
  • World's Smartest Man: Has been repeatedly stated to have the highest IQ of any Heisei Kamen Rider.

Tropes exclusive to him as Kamen Rider Build:
Are you Ready? Hagane no Moonsault!note  RabbitTank! Yeahhh!
Are you Ready? Shuwatto Hajikeru!note  RabbitTank Sparkling! Yea-Yeahhh!
Are you Ready? Uncontrol Switch! Black Hazard! Yabei!
Are you Ready? Overflow! Kurenai no Speedy Jumper!note  RabbitRabbit! Yabei! Haei!
Are you Ready? Kanzen Muketsu no Bottle Yarō!note  Build Genius! Sugei! Monosugei!

  • All Your Powers Combined: Genius Form lets him access the power of all 60 Fullbottles at will. This is first seen in #42 where Build is able to use the Diamond Fullbottle's shielding powers to defend against Evol's Steam Attack.
  • Awesome, but Impractical:
    • KeyDragon is the most powerful of the first ten Best Matches by a considerable margin, easily standing up to Night Rogue and Blood Stalk when other Best Matches can't. However, Dragon is so powerful that even Lock can't properly control it, with explosive results. Since Ryuga's unusually high compatibility with Dragon allows him to use it to achieve a Rider form all on its own, KeyDragon is swiftly retired, with Lock becoming Ryuga's backup Fullbottle of choice. Eventually gains the use of the form again as not just KeyDragon but as KeyDragon Hazard against Kamen Rider Evol in Dragon form! OH NO!
    • The Hazard Trigger's berserker state is as cool and powerful as it is terrifying, but its inability to tell friend from foe makes it vulnerable to any opponent tough enough to not get completely crushed by its opening salvo of finishers, as they can easily refocus its attention onto one of Sento's allies.
  • Badass Bandolier: The Gatling Fullbottle gives him armor on the left shoulder that evokes this.
  • The Berserker: Using the Hazard Trigger allows Sento to upgrade any Best Match into a solid black Hazard form. Using this form for too long will cause the user's mind to be overwhelmed, causing them to rampage and attempt to destroy everything in sight. Even Katsuragi thought it was too dangerous to ever use.
  • Big "NO!": The Hazard Trigger prompts the Build Driver to switch from its usual punctuation of the transformation with a loud "YEAH!" to one of these. It's entirely warranted.
  • Broke Your Arm Punching Out Cthulhu: Sento's plan in the penultimate episode empties out the Genius Bottle, leaving him unable to use it for the final battle.
  • Combat Pragmatist:
    • Part of what makes Hazard forms so terrifying is invoking this, as they trade Sento's usual flashy fighting style for a brutal and straightforward one with all of his immense brainpower suddenly focused on nothing but the most efficient way to kill everyone in sight. A sufficiently clever opponent can turn this trait against Sento by getting him to focus on murdering one of his own allies first.
    • Sento's not above this when he's in full control either - upon gaining a Flash Step in Genius Form, he starts spamming it gratuitously.
  • Combat Tentacles: The Octopus Fullbottle gives Build the ability to use the tentacles on the Twist Lash Arm mantle for long range grabbing.
  • Cool Sword: The Drill Crusher, a drill-shaped sword that can turn into a gun.
    • He builds another one for use by the NinninComic form called the 4-Koma Ninpoutou, which can switch between four attacks: Art of Cloning, Art of Flame, Art of Wind, and Art of Camouflage.
    • He builds yet another one for use with the RabbitRabbit and TankTank forms called the Fullbottle Buster, which like the Drill Crusher, can be used as a gun. Then again, "cannon" would be more appropriate than "gun"...
    • Sento also used the Beat Closer when using KeyDragon Hazard Form in #35.
  • Dangerous Forbidden Technique: The Hazard Trigger grants Sento access to Hazard Forms that exceed even Sparkling and the Sclash Driver riders in power, HawkGatling Hazard even being so fast it appears to teleport. The catch is that Sento's mind is overwhelmed by the Trigger when it's used, turning him into an emotionless berserker that won't let up until everything in sight is dead. Not defeated. Dead.
  • Deadly Rotary Fan: The Helicopter FullBottle grants one that can be used either for flight or as a sword.
  • Dual Wield: Any of Build's weapons can be used in any form, or even when not transformed at all, so he occasionally uses the Drill Crusher as an off-hand weapon for the 4koma Ninpoutou or HawkGatlinger. Sento's fighting style in RabbitTank Sparkling tends to cycle through many of Build's weapons in rapid succession, so he makes much more frequent use of two weapons at once in that form.
  • Elemental Powers: Every type of element there is has at least one Best Match associated with it, with some having more than one. If Build's current form can't use a given element on its own, the Drill Crusher can provide it on demand with a Vortex Break.
  • 11th-Hour Superpower: In the final episode, Sento uses the Gold Rabbit and Silver Dragon Fullbottles to transform into Build RabbitDragon Form, which is completely different from the Cross-ZBuild Form seen in the movie.
  • Evil Costume Switch: His Hazard forms are a Superpowered Evil Side, and their design is pitch black, spikier, and generally far more menacing than his base forms.
  • Evil Knockoff: The Build Driver is actually a good, though still lesser, knockoff of the Evol Driver.
  • Experienced Protagonist: By the time we first see Build in person, he's been at large for about a year.
  • Fashionable Asymmetry: Build's suit almost completely has the appearance of strips of color (or of black, for the undersuit) wrapping around him at a 45-degree angle.
  • Finishing Move: All of his Best Matches each allow him to use a Vortex Finish depending on the form, though certain weapons have attacks that can rival a Vortex Finish:
    • RabbitTank: Build dives underground to send a white energy chart flying up to the surface with the dotted line securing the enemy before leaping back up, and delivering a Rider Kick whilst riding the chart's line.
    • GorillaMond: After fabricating a wall of diamond, Build then punches it at full force at the enemy, shredding the foe with its shards.
    • HawkGatling: Build spins the HawkGatlinger's ammo drum, increasing the number of shots fired by ten every time and projecting a sphere around him until he hits one hundred. Upon hitting one hundred he begins firing at everything caught within the sphere's radius.
    • NinninComic: Depending on what mode the 4Koma Ninpoutou is in, Build can perform the following: Clone Jutsu note , Fire Jutsu note , Wind Jutsu note , and Stealth Jutsu note .
    • RocketPanda: Build fires up the Space Ride Arm and summons a white energy graph to wrap around the enemy, with him flying the trajectory of the graph while tearing them to shreds with Panda's claw at full force, repeatedly if needed.
    • FireHedgehog: Build extends Multi Deluge Gun on his Fire Engine arm into the enemy and fills them with water, then jumps and use his Hedgehog side's Spine Knuckle to pop them like a balloon.
    • LionCleaner: Build sucks an enemy in using the Long Range Cleaner until they are close enough to blast them with a lion-shaped energy blast from Lion's Gold Lio Gauntlet.
    • KeyDragon: Build traps his foe with chains from the Bind Master Key, then launches a powerful dark blue fireball.
    • KaizokuRessya: Build charges the Kaizoku Hassyar to its fourth tier, and fires a green energy train that rams into his foe, that also fires a series of blue discs.
    • OctopusLight: Build grabs his enemy with the tentacles on the Twist Lash Arm while blinding them with a rolling cloud of ink, then reels them in closer to use an electrified, blinding punch with his left hand.
    • RabbitTank Sparkling: In general it's an empowered kick. During its first outing, Build jumps high using Rabbit's foot, then summons a wormhole behind them to suck Blood Stalk's energy snakes in to trap them, then hits them with a powerful kick that then sends energy "bubbles" to bombard Stalk with enough for him to drop his transformation. Against Night Rogue, it was a more simple Dive Kick. Against Cross-Z, it's a simple back kick using Tank's foot.
    • PhoenixRobo: Flies using Phoenix's wings, he wreathes himself in flames and strike an enemy with Robot's hand repeatedly.
    • SmaphoWolf: Build summons Smartphone's application screen surrounding the enemy, then a virtual Wolf appears from the screen and attacks.
    • Black Hazard: It has two finishers:
      • Overflow: A dark energy-infused Rider Punch delivered either as a single blow, a series of rapid strikes, or a Touch of Death. When used as SmaphoWolf Hazard, the punch is accompanied by the image of a gigantic black wolf's head howling at the target. When used as HawkGatling Hazard, Build performs a series of blasts with the Hawk Gatlinger while flying around the enemy with the Sollstall Wings.
      • Hazard Finish: Build coats his right leg in purple dark energy before delivering a powerful kick. When used as HawkGatling Hazard, Build traps the enemy in a black cloud and performs a series of purple blasts with the Hawk Gatlinger.
    • RoseCopter: Build detaches the helicopter blade from his back, then covers it in red energy rose vines as it starts spinning before flying at the enemy for a slashing attack. An alternate version has Build instead grapple the enemy with Rose's vine whip before delivering an aerial shoulder tackle that shreds them with Helicopter's spinning blade.
    • KirinCyclone: Build summons an energy giraffe neck and attacks the enemy with it.
    • RabbitRabbit: Jumping into the air, Build stretches his leg towards the opponent, and pulling his body towards his foot, connects with the target, with the resulting impact sending his opponent flying.
    • TankTank: Build transforms his legs into tank treads, then launch a volley of bombardment from Fullbottle Buster Cannon Mode while circling the hapless foe.
    • Genius Form: It has three finishers:
      • Genius Attack: Build channels energy into the red, magenta, and orange parts of his body before delivering a punch covered in red energy. It's so powerful, it can even temporarily neutralize an opponent's Nebula Gas.
      • Genius Break: Build channels energy into the blue, cyan, and violet parts of his body before delivering a side kick covered in blue energy that creates a shockwave upon impact and sends the enemy flying.
      • Genius Finish: Build channels energy into his entire body before performing an enhanced version of RabbitTank Form's Vortex Finish, with the graph being rainbow colored and Build emitting rainbow-colored gas in order to accelerate into the enemy. If used against a Lost Smash, he can remove the Nebula Gas inside said person without the risk of killing them. Adding the Hazard Trigger allows him to revert black Lost Bottles back into their original state.
    • In addition to these, the Drill Crusher has a different Vortex Break finisher for each of the 60 Fullbottles, normally some form of slash or thrust enhanced by the bottle's ability.
    • The FullBottle Buster has 60 different FullBottle Break finishers for each bottle, akin to the Vortex Break finishers of the Drill Crusher, but can additionally load more bottles in after the first to enhance the attack: Just Match Break for two, Miracle Match Break for three, and Ultimate Match Break for four. The Full Full RabbitTank Bottle, which is big enough to take up all four slots, performs the Full Full Match Break finisher when loaded, with its effects depending on Build's current form.
  • Flash Step: Genius form can move at speeds that put RabbitRabbit to shame.
  • Flight: Hawk (when it's used with Gatling, the wings are even larger), Rocket, Phoenix, Helicopter, Jet, and UFO's powers.
  • Fragile Speedster: HawkGatling, NinninComic and KaizokuRessya all fall into this archetype, sacrificing strength and durability for increased speed relative to other Best Matches. All three happen to also rely on external equipment devised by Sento, making up for their lack of physical power through their weapons.
  • Fusion Dance: Cross-ZBuild is him and Cross-Z merged into one.
  • Gatling Good: The Gatling powers, and Sento developed the Hawkgatlinger to go with them.
  • Gemstone Assault: Part of the Diamond powers involve creating diamond crystals and sending them at enemies. It can also be used to enhance defenses, as Rogue proves in their proxy battle.
  • Glass Cannon: HawkGatling and KaizokuRessya make up for their low physical strength and complement their high speed with weapons that allow them to unleash immense firepower from a distance.
  • Harmful Healing: Genius has the power to "heal" people of Nebula Gas affliction, potentially lowering their Hazard Levels (read:overall strength). Said treatment is often administered as a Rider Kick.
  • Heroes Prefer Swords: Unusually for a Heisei Kamen Rider (aside for Gaim), he's got three sword-type weapons: the Drill Crusher, 4-Koma Ninpotou, and Fullbottle Buster. Various Fullbottles such as Lock or Helicopter grant swords or swordlike weapons of their own as a component of the suit.
  • Highly Visible Ninja: NinninComic is... bright purple and yellow.
  • Hover Board: The UFO FullBottle gives him an energy variant.
  • I Have Many Names: Thanks to Sento's modifications to the belt, the Build Driver makes a show of shouting out an Red Baron for each one of the thirty Best Matches and other forms he uses - even the ones not shown in the show.
  • Jack-of-All-Stats:
    • RabbitTank is the most well-rounded of the Best Matches, and also the most stable, proving compatible with enhancements that produce explosive results when used with others. That is why Build's upgrade forms are using RabbitTank as the base.
    • Many other Best Matches such as RocketPanda, LionCleaner, and SmaphoWolf are also portrayed as well-rounded, but have additional weapons and abilities that RabbitTank lacks. RabbitTank eventually sees its upgrades take the place of the new standard as the threats escalate.
  • Light 'em Up: The Light Fullbottle has this ability. Also as a bit of Shock and Awe properties as well.
  • Lightning Bruiser:
    • RabbitTank Sparkling gets to enjoy a brief tenure as one, before escalating threats render it simply the new baseline for a Jack-of-All-Stats.
    • The Hazard Trigger turns any form into one of these regardless of its original characteristics. Between RabbitRabbit and TankTank, one emphasizes speed and the other power, but both are this trope relative to all of Build's earlier forms.
    • PhoenixRobo possesses the same flight and long-range capabilities as HawkGatling through its pyrokinesis, but unlike that form it also possesses enormous melee and defensive strength, making it the strongest of all the "vanilla" Best Matches.
  • Luckily, My Shield Will Protect Me: The Smartphone FullBottle gives Build a shield. In the form of a giant smartphone.
  • Making a Splash: Firetruck, Whale, and Pirate's powers.
  • Master of None: Any of Build's mismatched Trial Forms. They don't necessary clash, it's just that their individual punching and kicking power are not as high as compared to their Best Matches. Zig-Zagged as the abilities of the halves of the Trial Forms can create forms tailor made for certain purposes, such as Firetruck and Whale Trial Form improves water-manipulating abilities of both sides.
  • Mid-Season Upgrade: The Hazard Trigger allows Build to upgrade any Best Match into "Super Best Match" Hazard versions, which keep the eyes of the original forms but otherwise sport a sleek uniform black suit. RabbitTank Hazard can be further upgraded using the Full Full RabbitTank Bottle in place of the normal bottles to achieve two super forms, RabbitRabbit and TankTank.
  • Mighty Glacier: GorillaMond and FireHedgehog fall into this category, sacrificing speed and mobility for superior physical power and durability. The former does this primarily through brute strength, the latter through abilities that make approaching Build to attack a near-impossibility while inflicting Gradual Grinder damage.
  • Mismatched Eyes: Build's forms mostly have this, with them being different colors and shapes depending on what he uses for that side. Even the ones that are the same color seem to be different shades and are most definitely different shapes. The only exceptions to this are RabbitRabbit and TankTank, which deliberately use the same respective essence twice in each form.
  • Multiform Balance: Build follows the Kamen Rider OOO model here, with specific combinations (Best Match) having the most optimized specialization and given more focus as the result.
  • Oh, Crap!: The Build Driver has one whenever the Hazard Trigger is used. The last part of any Hazard form's transformation sequence is the Driver calling the thing uncontrollable and dangerous.
    Uncontrol Switch! Black Hazard! OH NO!
  • Playing with Fire:
    • The Firetruck Fullbottle gives Build the ability to either shoot water or fire.
    • The Dragon Fullbottle gives Build this, but not to the extent that Cross-Z can use. Also the flames are blue.
    • The Phoenix Fullbottle also gives Build this ability as well.
  • Power Fist:
    • The Gorilla powers give him the Muscle Glove, an oversized fist suited for strong punches.
    • The Robot FullBottle gives him a big robot fist on his left arm.
  • Power Gives You Wings: Any use of Hawk or Phoenix FullBottles, for obvious reasons.
  • Primary-Color Champion: His main form, RabbitTank, is primarily red and blue - with a dash of yellow on his belt.
  • Restraining Bolt: The Full Full RabbitTank Bottle essentially acts as this for the Hazard Forms, as in addition to acting as a power up, it cancels out the corrupting nature of it.
  • Rollerblade Good: The Tank half of Build's default form appropriately has tank treads on his sole that allow speedier movement or for a damage boost. TankTank adds larger treads to both of Build's knees that serve the same purpose.
  • Rubber Man: RabbitRabbit, much like Maximum Mighty X before it, can elongate any of its limbs at will.
  • Rule of Three: One needs a minimum Hazard Level of 3 if they have any hope of transforming using the Build Driver.
  • Shoo Out the Clowns: Many of his goofier Best Matches such as OctopusLight and NinninComic are made permanently unavailable to him in the second half of the show after the panels containing them are attached to the Pandora Box. He later gets them back, but only briefly before they're taken again, and doesn't use them to transform during that time.
  • Smug Super: While still present untransformed, Sento's more cocky and assured of himself while suited up.
  • Spam Attack: Part of the terror of the Hazard Forms is that they spam finishers to devastating effect, usually in the form of breaking an opponent's defenses with an Overflow before attempting to murder them with a Hazard Finish.
  • Spike Shooter: Hedgehog's powers, manifesting in the Spine Knuckle and Build Spine Shoulder pauldron. He can use it in the Drill Crusher Gun mode, which enables the weapon to shoot them.
  • Spring Coil: The Rabbit half's leg is equipped with one for super jumping. Fittingly, the actual foot has a rabbit paw print as well, that is often imprinted on whatever Build walks on, even the Strong Smash in #1. In fact, Build's Rider Ability in Climax Fighters is his Rabbit Jump. RabbitRabbit adds coils to all four of Build's limbs to enable his new Rubber Man powers.
  • Squishy Wizard: NinninComic and OctopusLight fall into this archetype. The former is a Fragile Speedster that lacks the Glass Cannon capabilities of the other high-speed Best Matches, but instead possesses a wide array of utility powers through its ninja techniques. The latter would be a Master of None if not for its abilities, which allow it to drown its opponent under hampering conditions with ink, light, and electrical shocks all delivered from a distance.
  • Super Mode: Genius form.
  • Superpowered Evil Side: The Hazard forms are much stronger than even RabbitTank Sparkling, but also turn him into an amoral berserker.
  • Super Speed: RabbitRabbit form allows Build to move at high speeds, allowing him to run faster and even dodge attacks.
  • Super Toughness: Diamond's abilities allow for this, in addition to summoning a storm of crystals.
  • This Is a Drill: Build's Drill Crusher, which he uses as a sword and gun.
    • The Rhino Beetle (Kabutomushi) Fullbottle also equips one on his arm.
  • Variant Power Copying: Build can steal his enemies' Nebula Gas Essences and save it for use later once purified, though the mechanics of how he uses the Essences are different. This likely has something to do with the purification process.
  • Weapon of Choice: All of Build's forms can use any weapons summoned by the Build Driver, although some weapons are more effective when used by certain Best Match form. Due to being built by Sento himself rather than the weapons being formed by the suit, the weapons have been used a few times by Sento and Ryuga as themselves, without any visible drop in efficiency:
    • His default weapon is Drill Crusher, which has two modes: Sword and Gun.
    • The exclusive weapon of HawkGatling form is Hawk Gatlinger.
    • The exclusive weapon of NinninComic form is 4-Koma Ninpotou.
    • The exclusive weapon of KaizokuRessya form is the crossbow Kaizoku Hassyar.
    • RabbitRabbit and TankTank come with the Fullbottle Buster, a transformable weapon akin to the Drill Crusher on steroids. Unlike the former, this weapon is part cannon, not gun.
  • Weapons That Suck: The Vacuum Cleaner (Soujiki) Fullbottle equips him with one, which is called the Long Range Cleaner.
  • Whip It Good: The Rose FullBottle gives him a thorn whip for long range attacks.
  • Wolverine Claws: Panda, Bear, Wolf, and Tiger each grant their own variant of this ability.
  • Yellow/Purple Contrast: His Best Match NinninComic Form uses the Ninja and Comic halfbodies. The purple Ninja halfbody has the Onmitsu scarf that can wrap his entire body to camouflage himself with the local scenery, but the yellow Comic halfbody do the opposite with its flashiness when it creates highly visible Manga Effects when using its powers. The form's description as "Shinobi Entertainer" in its Transformation Name Announcement lampshades the contrast; a shinobi operates in concealment while an entertainer thrives in the spotlight.

    Ryuga Banjo/Kamen Rider Cross-Z 

Ryuga Banjo/Kamen Rider Cross-Z

Portrayed by: Eiji Akaso (live), Eitoku (suit)
"I feel like there's no way I can lose!"

A former prize fighter disqualified for cheating, later convicted of murdering Takumi Katsuragi, a scientist investigating the Pandora Box. Like Sento, he was experimented on, but managed to escape and now takes refuge with Sento. He accompanies Sento to investigate the mystery behind Katsuragi's murder, arguing all the way.

Using the Cross-Z Dragon as an add-on for the Build Driver, he transforms into Kamen Rider Cross-Z. Using the Dragon Sclashjelly in the Sclash Driver, he can instead transform into Kamen Rider Cross-Z Charge. Later, he upgrades his basic Cross-Z form into Cross-Z Magma, using the Cross-Z Magma Knuckle in conjunction with the Dragon Magma Fullbottle.

Tropes that apply to him in general

  • Ambiguously Human: It's noted by several characters how odd his exponentially increasing Hazard Level is. #30's Cliffhanger ends on the revelation that Banjo might not be human at all before #31 reveals that he's a Half-Human Hybrid due to Evolto's attempt to take control of his mother with the segment of his DNA that he sent back with the Mars Rover one month into her pregnancy.
  • Anti-Hero -> The Hero: Ryuga starts the show with decidedly selfish motivations for fighting against Faust, but steadily begins to mature through seeing Sento's heroism in action. It's not until he grows past his antiheroic status that he can become a Kamen Rider in his own right. Eventually, he becomes a straight up hero and essentially cites Sento as his role model. This is concluded by him trying to sacrifice himself in the final battle while repeating Sento's speech from #3.
  • Apocalypse Maiden: Blood Stalk's been grooming him since day one to be his, or rather Evolto's, vessel so he can have enough power to destroy the world with the Pandora Tower.
  • Badass Abnormal: Faust's experiments infused Ryuga with enough Nebula Gas to modestly enhance his already impressive physique, enough to fight the robotic Guardians with ease, though these boosts pale in comparison to those possessed by full-fledged Smash. More importantly, though, the infusion allows Ryuuga's Hazard Level to steadily grow to the point where he can use the Build Driver.
    • Empowered Badass Normal: Even before the infusions, Ryuga was a talented boxer. Due to being half-Blood Tribe, he was actually this from the moment he was born.
  • Berserk Button: With his hot temper, it's no wonder Ryuga has several of those.
    • Don't call him an idiot. He's aware of it, but doesn't appreciate being called that.
    • Don't call him a murderer. He will punch (or headbutt) it out of you.
    • Don't insult/hurt Sento and Misora. 1) Only he can call Sento out on his crap. 2) How dare you hurt Misora!
  • Better Than New: In #30, Stalk blasts Ryuga with his Martian energy powers, destroying the Dragon Sclashjelly. However, the blast causes the gel inside the packet to harden into a rock-like substance, which eventually breaks open to reveal the Dragon Magma Fullbottle, giving Ryuga a new form that's far stronger than Cross-Z Charge.
  • Bullying a Dragon: One can't deny that Ryuga's got balls for picking fights with opponents that are far stronger than him.
  • Butt-Monkey: Got caught for cheating during a match and was banned from pro-fighting, was blamed for murder, lost his girlfriend, frequently teased by the gang... the list goes on for poor Ryuga.
  • Character Development: It takes eleven episodes of slow and steady growth for Ryuga to shed enough of his selfishness that the Cross-Z Dragon will recognize him as worthy of becoming a hero. Even after that, his growth steadily continues, with his speech at the end of #32 and the risk he takes accompanying it showing just how much he's blossomed into a true Kamen Rider.
  • Comes Great Responsibility: Learning this lesson is necessary for him to become Cross-Z, as the dragon won't respond until he does.
  • Despair Event Horizon: Following Kasumi's death, Ryuga just stops caring what happens to him until Sento snaps him out of it. He recovered from it only so much as to be able to function without anyone noticing anything out of ordinary for most of the time, but it still haunts even late into the story.
  • Determinator: While Sento invents new gadgets to help him fight better, Banjo tends to get by via throwing himself against an overwhelming problem until he becomes strong enough to overcome it. He can even force his body to grow back missing DNA by punching his problems hard enough.
  • Deuteragonist: Despite Sento insisting that he (and everyone else) are just the "sub-characters", Ryuga ends up being almost equally as important to the narrative as Sento to the point where at times one could mistake him as The Hero instead of Sento.
  • Dumb Muscle: A talented fighter, but not very bright. Sento does assure him that he can't be that dumb if he recognizes the fact, as truly stupid people don't even realize they're stupid - before pointing out that his fly had been down the entire time. He probably veers more into Book Dumb than just outright dumb and his short temper gets the better of him.
  • Emotional Bruiser: His fighting abilities are undeniable, even if often impaired by trying to punch high above his league. Stoic is not a word to describe him with as he is quick to show his emotion (as evident by his constant bickering with Sento or headbutting Tatsuya). This gets him into big trouble often, but is still refreshing to see considering the number of stoics among secondary riders.
  • Enemy Mine: Of the two Riders, he's the most willing to work with Gentoku during Hokuto's invasion because he sees it as the quickest way to end the war and bring peace back to Japan.
  • Escaped from the Lab: He escaped on his own from Faust's lab just before he was turned into a Smash. It was the same lab Sento was held in before.
  • Face–Heel Turn: In Kamen Rider Build: Be The One movie. Thanks to the Blood Clan brainwashing him, Ryuga has effectively betrayed Sento and now works for Touto's new Governor...who, mind you is also the movie's Big Bad.
  • For Want of a Nail: Actually a plot point in the finale. Because the old world's Ryuga Banjo had Evolto's DNA in him, he technically counts as a different person (the second Ryuga Banjo from the new world has black hair, whereas the first one from the old world has his regular brown hair), and much like Sento, who doesn't have a counterpart, he retains his old memories.
  • Gratuitous English: A few of his shirts.
    You look better on social media. (#2)
  • Half-Human Hybrid: His mother was infected by Evolto's body that hitched a ride back to Earth on Japan's first Mars Probe and the end result was Ryuga being born after two months and having an unknown alien genetic structure composing part of his genetic code, meaning he's a Human/Blood Tribe hybrid. Worth noting is this is so ingrained into him that Evolto actively trying to absorb all of the DNA needed for him to transform fails as Ryuga merely regenerates more.
  • Heartbroken Badass: The emotional fallout from Kasumi's death drives Ryuga as much as clearing his own name.
  • Heroic Self-Deprecation: He hides a heap of self loathing under his boisterous attitude, blaming himself for Kasumi's death, thinking no one would care if he died and feeling inadequate compared to Sento.
  • Hidden Depths:
    • In spite of his Dumb Muscle status, he can still put two and two together at times and play the 'common sense' to Sento. He immediately figures out that Best Matches follow an Biotic + Abiotic formula, something Sento had overlooked as too obvious to possibly be the solution.
    • He can also be pretty good with words if he thinks for a moment as the Get A Hold Of Yourself Man moment of #6 or the pep talk of #15 show.
    • In #2 and #30, it appears he holds a lot of fondess of his childhood. Whenever he describes the circumstances of his birth, a bright smile is always on his face.
  • Hot-Blooded: Very much so. It's in his nature after all.
  • Hypocrite: In #5, he says (paraphrased) "Sento is so selfish for focusing on his own problems... he should be focusing on my problems!" This doesn't qualify as Hypocritical Humor because there's nothing funny about him knocking out Sento and turning the Victim of the Week back into a Smash in the hopes that it'll lead him to Faust's base.
  • Hybrid Power: Katsuragi, while studying Ryuga, determined that his unique genetics meant that his ever escalating Hazard Level might one day allow him to surpass Evolto in power. This eventually came through when he used the Muscle Galaxy Fullbottle to transfom into Cross-Z Evol, whose potential exceeds both Evolto and Killbus.
  • Hypocrite Has a Point: While he wants Sento to focus solely on his problems can be seen as selfish, it makes sense, because as far as the general public is concerned, he's a murderer and can't go outside without risking getting caught by Guardians, sent back to jail and more than likely, be experimented on by Faust again.
    • Also don't forget that Faust caused all his problems (including blaming him for murder and turning his sick girlfriend into a Smash, causing her death), meanwhile the only problem Sento has is his amnesia.
  • Hypocritical Heartwarming: Only he and Misora can call Sento out on his crap to make him realize it is, well.. crap. Anyone else does so only to hurt Sento and Ryuga will make sure they know he doesn't tolerate that.
  • Idiot Hero: It's almost baffling how dense he is. His critical thinking skills are similarly abysmal considering that he usually lets the first thing he sees about a situation be what paints his perception of it. For example: "There's evidence that Sento might have been the one who killed Katsuragi, therefore he needs to turn himself in no questions asked." or "Katsuragi might have been responsible for the Smash experiments for the purpose of finding someone who can use the Build Driver, therefore he definitely was responsible and was a horrible devil scientist."
  • Instant Sedation: Being injected with sedative by a prison guard gives him enough time to turn around and rise his hands in defense before going out like candle.
  • It's All About Me: Early in the series he's like this, treating his quest to Clear My Name as the single most important thing in the world and dismissing everyone else's concerns, including Sento's amnesia and Nabeshima's family being used as hostages, as insignificant in comparison.
    • Revenge for his girlfriend's death is also high on the list, but as times passes, it moves to similar level with concerns of everyone else.
  • Jerk with a Heart of Gold: Regular fights and abrasive attitude aside, he cares about Sento and Misora. The fighting is not always a bad thing anyway. He and Kazumi have started out decidedly not liking each other even when they were technically on the same side already, but over the time turned into Vitriolic Best Buds, sometimes crossing into Bash Brothers.
    • In #11, Misora tells him that to use the Cross-Z Dragon, he needs strong emotion and uses an example of what he felt when he protected her from Faust. Ryuga tells her off, but can't deny events of #9 (trying to cheer her up and protecting her from Night Rogue).
  • Last-Name Basis: Everyone refers to him as Banjo. On the flip side, he mostly uses first names.
  • Like Brother and Sister: Misora acts as a substitute little sister to him and Sento.
  • Luke, I Am Your Father: It's eventually revealed the alien that sired him was part of Evolto, meaning in essence, Evolto is his father. Evolto outright calls him "my spawn" after Ryuga manages to regenerate the DNA necessary for using his powers.
  • Meaningful Name: The kanji for 'Ryuga' are 'dragon me'. Fitting considering that he is dragon-themed rider, Cross-Z, and was initially motivated mainly by his own concerns. note 
  • Morality Pet: According to Misora, Sento built the Cross-Z Dragon to serve as a literal one for Ryuga. Misora herself counts as one as she tried to talk Ryuga out of being mad at Sento at couple points of time in past and Ryuga cares about her.
  • Muscles Are Meaningless: He is skinny, but has great physical strength, thanks to Faust's experiments.
    • This lampshaded by Kazumi in #26. Upon being told to work muscles into his insults (like when Sento calls Ryuga meathead/musclebrain), Kazumi asks where he is supposed to see those muscles.
  • Mythical Motifs: Aside from his name, his three braids across the scalp seems to evoke a dragon's claw from the back of his head.
  • No Indoor Voice: He can go from normal volume to loud in a moment, usually as a result of getting angry or startled.
  • No Sense of Personal Space: Side effect of him being capable of getting into everyone's face really quickly. He also gets this (like touching shoulders distance) close to Sento, who doesn't seem to mind for most of the time.
  • Paper-Thin Disguise: Half of his disguises verge on Clark Kenting.
  • Punch! Punch! Punch! Uh Oh...: A logical outcome of his way of thinking - "If punching doesn't work, punch harder."
  • Red Oni, Blue Oni: The red to Sento's blue, not only for his hot-blooded and impulsive personality, but also with Cross-Z Magma in general.
  • Running Gag: His casual outfits and disguises are a frequent source of comedy as his wardrobe is left at the mercy of whatever is lying around the cafe.
    • He also has the best luck when it comes to finding Best Matches, randomly picking out Bottles he managed to pair HawkGatling and NinninComic with just a single try, which constantly frustrates Sento who needed multiple tries. Ryuga even lampshaded it himself when handing Sento his Dragon Fullbottle with the Lock Fullbottle during a badass moment, turned out to be yet another Best Match.
  • Screams Like a Little Girl: As a Running Gag, he usually lets out a yelp when he's startled by the purifier machine going off. He's also screaming shitless when Sento takes him inside a cave and flying with RocketPanda.
  • Spanner in the Works: Evolto's attempt to possess his mother instead resulted in the piece of him sent to Earth merging with Ryuga and making him a Half-Human Hybrid. Thus instead of having another half of him on Earth preparing the way for his arrival he could recombine with upon arrival, Evolto had to work a lot harder to become complete and ultimately can't strip Ryuga of his powers because Ryuga's body can just replace the DNA he stole.
  • Technician Versus Performer: The Performer to Kiryu's Technician, though the narrative tends to show both of their virtues and shortcomings in this dynamic.
  • Throwing the Fight: This resulted in the ignoble end of his prize fighter career. The reason he did so was to get money to pay for treatment for his girlfriend.
  • Tragic Keepsake: The Dragon Fullbottle, which was made from the essence of the Burn Smash and as such is the last remaining reminder of his girlfriend. Turns out it can do more than that. So much more.
  • Trauma Conga Line: He loses his career trying to get money for his girlfriend's operation, gets framed for murder because said girlfriend was tricked into sending him there, gets abducted from prison and used as a guinea pig for horrific experiments, escapes only to be treated as a fugitive from the government and sees his girlfriend turned into a Smash and die in his arms because her body was too weak to survive being turned back into a human. That's just the first two episodes. Ryuga has it tough.
  • Unlimited Wardrobe: In contrast to Sento's one outfit, Ryuga has new clothes every other episode. On the other hand, these clothes are often more or less ridiculous disguises that Soichi or Misora whipped up.
  • You Have to Believe Me!: Says this word for word to Sento in #1. The fact that he's a convicted murderer and clearly not in good mental state doesn't help. On the other hand, he has a pretty good reason to be freaked out so it's no wonder he doesn't make much sense.

Tropes exclusive to him as Kamen Rider Cross-Z/Cross-Z Charge/Cross-Z Magma/Cross-Z Evol:
Are you Ready? Wake up Burning! Get CROSS-Z DRAGON! Yeah!
Click here to see Cross-Z Charge 
Tsubureru! Nagareru! Afurederu!note  Dragon in Cross-Z Charge! Buraa!
Click here to see Cross-Z Magma 
Are you Ready? Gokunetsu Kinnikunote  Cross-Z Magma! Achachachachachacha Acha!"
Click here to see Cross-Z Evol 
Are you Ready? Ginga muteki no kinniku yarō! Cross-Z Evol! Panēi! Maji panēi!

  • Cool Sword: Beat Closer. By pulling on the bottom grip, it can perform stronger attacks.
  • Deadly Upgrade: The Sclash Driver draws its overwhelming power from exposing the user to the raw, unfiltered effects of Nebula Gas, which has the same effects on the user's personality as being near the Pandora Box when it was activated. Even the first usage causes Banjo to take on a berserker's fighting style and adds a menacing growl to his voice while wearing the suit, and repeated usage will turn the user into a Blood Knight who can think of nothing but battle. Making matters worse, its mental stresses come with accompanying physical stresses, enough so that just the act of transforming with it for the first time is an agonizing experience and prolonged battle will often see Banjo be overwhelmed by the strain. It takes six episodes of frequent usage for Banjo to finally acquire an immunity to the physical stresses of the Driver.
  • Discard and Draw: His Sclash Driver and Dragon Jelly get destroyed, forcing him to switch back to the Build Driver, but he gets the Magma Knuckle, which not only is a powerful weapon, but also lets him access his Super Mode.
  • Evil Sounds Deep: Wearing the Sclash Driver makes Banjo dramatically more aggressive than he is normally, and gives his voice a rough growl to match.
  • Finishing Move:
    • Build Driver: Draconic Finish, with two variations:
      • The Rider Kick version: Banjo summons a blue and orange energy Chinese dragon that flies behind him, then he jumps up as the dragon breaths fire, with said fire pushes Banjo to the enemy, then he delivers a roundhouse kick whilst his foot is covered in blue energy (basically a combination of Ryuki/Ryuga's Final Vent (the dragon summoning and the push) and Gatack's Rider Kick (the jumping roundhouse kick)).
      • The Rider Punch version: Banjo charges up a blue Chinese dragon-shaped energy in his right hand before delivering a punch to the victim.
    • Beat Closer: It has three finishers, all of which are delivered by a powerful Rider Slash. The 3 finishers are determined by how many times Banjo pulls the handle, and if a Fullbottle is inserted in the hilt, which increases their power: Smash Hit (pulls handle once), Million Hit (pulls handle twice), and Mega Hit (pulls handle thrice). All three become "Slash"es when the Beat Closer is augmented by inserting a Fullbottle.
    • Scrap Break: Similar to the Build Driver, Cross-Z Change can either preform a flying side kick, or a punch covered in cyan and orange energy.
    • Twin Breaker: Like the Beat Closer, it has multiple finisher when he uses a FullBottle and a Sclashjelly, which depends on the weapon mode he is using and what he placed into the Twin Breaker. He also has an exclusive Let's Break finishing move when he plugs the Cross-Z Dragon into the Twin Breaker.
    • Cross-Z Magma: Banjo's Super Mode has the Volcanic Attack, a bog-standard Rider Kick with the twist of forming dragons of magma around him that allow him to melt through anything in his way before surrounding him during his downwards descent to counter incoming projectiles and to give his kick a red-hot explosive enhancement. And his second move is Volcanic Finish, where Cross-Z performs a series of rapid flaming punches before delivering a volcanic final punch.
    • Cross-Z Magma Knuckle: Whether it's as regular Cross-Z or as Magma, the Knuckle can perform the Volcanic Knuckle Rider Punch with any Fullbottle, with the special effects surrounding the attack depending on the bottle.
    • Blizzard Knuckle: This variant of the Magma Knuckle instead uses a special Glacial Knuckle finishing move, which is similar to the Volcanic Knuckle but strong enough to damage Evolto in Black Hole form.
    • Cross-Z Evol: This form has three separate finishers.
      • Muscle Finish: Cross-Z Evol summons an enormous energy dragon, then delivers a Megaton Punch.
      • Galaxy Finish: Cross-Z Evol warps to an enemy and slams them into a black hole, before detonating it.
      • Muscle Galaxy Finish: Cross-Z Evol does a Rider Kick, and while he's still pressing his foot against his victim, Cross-Z and Evol momentarily split, before merging and tearing through the enemy, causing them to explode.
  • Flight: Using the Taka Fullbottle in the Sclash Driver can grant Cross-Z Change orange energy wings. Cross-Z Magma has its own wings built in.
  • Fusion Dance:
    • Cross-ZBuild is him and Build merged into one.
    • Later on, Cross-ZEvol operates under the same principle.
  • Gathering Steam: How Ryuga’s rapidly increasing Hazard Level manifests. So long as he remains in Rider form and combat long enough while properly motivated, his power will continue to rise until he can overwhelm the opponent. This puts him in an interesting back and forth with Sento, as while Sento's upgrades give him an initial edge in strength, in every case Ryuga's rapid growth lets him close the gap by increasing his raw power. By the end of the system, Ryuga's Hazard Level passes 7, putting him on equal footing with Build Genius (the first time in years a secondary rider's final form hasn't been massively surpassed by the primary's. In fact he reached level 7 first.) and making him superior to every other rider in the series bar Evol Black Hole. Later, during his fight with Killbus (an opponent stronger than even Evol Black Hole), Evolto takes advantage of this by tricking him into rapidly elevating his Hazard Level. This allows him to transform into Cross-Z Evol, currently the strongest of the Build World rider forms and the first time in recent memory a secondary rider has eclipsed a primary rider's ultimate form.
  • An Ice Person: Using the Blizzard Knuckle allows Cross-Z to use special ice powers, although it's soon revealed that the Knuckle's not really meant for him: rather, it's meant as an upgrade for Grease.
  • Jack-of-All-Stats: On paper, Cross-Z's parameters are enormous compared to Build's, surpassing most of Build's various first-quarter forms. In practice, he's only roughly as strong as a typical Best Match, and while he fares well against Smash, he loses regularly to both Night Rogue and Blood Stalk, who have more experience and stronger abilities than Cross-Z can match without the element of surprise. Despite being only a minuscule statistical upgrade on paper that just barely matches RabbitTank Sparkling, Cross-Z Charge's battle performance is monstrously strong for its time, far exceeding Sparkling's. Ultimately his seemingly ceilingless hazard level potential means that any of his forms can grow well beyond their initial levels, with even base Cross-Z being able to overwhelm one of the Kaisers using the Magma Knuckle.
  • Lava Adds Awesome: The magma that Cross-Z has access to in his Cross-Z Magma form allows him to magnify his attacks with intense heat and create magma dragons for his attacks.
  • Lightning Bruiser: Cross-Z Magma is a gigantic upgrade over Cross-Z Charge in every aspect, towering over RabbitRabbit and TankTank for raw physical prowess. With Banjo's ever-escalating Hazard Level surpassing any normal human's limitations, Magma soon becomes so powerful that it can even stand up to Evol and Genius.
  • Mid-Season Upgrade: Switching from a Build Driver to a Sclash Driver and using the Dragon Sclashjelly allows him to upgrade into Kamen Rider Cross-Z Charge.
    • Great Cross-Z plays with this. By the time he gets it, Ryuga already has his Super Mode. However, Great Cross-Z is a straight-up upgrade of regular Cross-Z and replaces it as his base form, and while Cross-Z Magma remains his most powerful form, it's apparently even more powerful now.
  • Playing with Fire: Most of Cross-Z's attacks are accompanied by blue flames. Cross-Z Charge no longer has them outside of finishing moves. Cross-Z Magma plays it up more as it has magma in the name.
  • The Power of Love: Both his Dragon Fullbottle and Jelly were derived from the Smash essence of his late girlfriend. As a result, he's the only one who can use them safely.
  • Power Fist: The Cross-Z Magma Knuckle can function as this as well as the add-on necessary for Ryuga to use his Cross-Z Magma form.
  • Power Gives You Wings: A running gag is how this is averted. In spite of being a dragon-themed Rider, Cross-Z’s default form has no wings, making him late when the others fly. Finally played straight with Cross-Z Magma.
  • Spell My Name with an "S": Prior to the reveal of the official romanization of his name, it was spelled as Claws, Close, or Cross. Amusingly, the merchandise that the official romanization was revealed on wasn't what you'd expect (his Transformation Trinket), but a pair of Goofy Print Underwear.
  • Story-Breaker Power: Cross-ZEvol, which incorporates a fused Evolto, is as strong the ridiculously powerful Killbus - who can easily handle Cross-Z Magma (stronger than initial Evol Black Hole) and Evol Cobra in a two on one fight.
  • Super Mode: Ryuga eventually returns to the Build Driver, this time enhanced by the Cross-Z Magma Knuckle and using it to gain access into Cross-Z Magma form.
    • Banjo gained a second Super Mode using the Muscle Galaxy Full Bottle to turn into Cross-Z Evol.
  • Swiss Army Weapon: The Twin Breaker he uses as Cross-Z Charge has a Beam Mode and a close range Attack Mode.
  • Unskilled, but Strong: Compared to Sento, Ryuga is a brutish fighter and lacks access to Build's wide array of situational tricks. However, his Hazard Level grows at an unrivaled rate, surpassing Sento's by #19 despite Sento having far more experience. Such is Ryuga's rate of advancement, in fact, that several other characters know they're on a fairly strict time limit to defeat him before they no longer can.
  • When All You Have is a Hammer…: Since Sento hoards most of their FullBottles, Banjo typically only has access to the Dragon and Lock combo components, if he even has those. Without his partner's diversity of options, Banjo has just one tactic in battle: to punch his problems harder and force his Hazard Level to rise until he can overwhelm his opponent with brute force. That said, he relies on this tactic for a good reason: it always works. No matter how desperate the situation, Banjo can accomplish seemingly impossible feats through sheer grit and willpower.
  • Wrecked Weapon: His Sclash Driver gets destroyed when he uses his own body as a shield to defend Vernage from Stalk.

    Kazumi Sawatari/Kamen Rider Grease 

Portrayed by: Kouhei Takeda (live), Satoshi Fujita (suit)
"I'll crush you with the fire burning in my heart!"

Hokuto’s first Kamen Rider as a result of the leader’s alliance with Blood Stalk, who gave them a Sclash Driver and the means to make the Robot Sclashjelly. He's a government-funded assassin. Later sides with the nascita crew to fight Seito when they invade his homeland.

Tropes that apply to him in general

  • Affectionate Nickname: Parodied. After joining the Touto Riders, he's insistent on at least Ryuga calling him "Kazumin". Also played straight in his insistence on calling Misora by her Idol name Mii-tan despite now knowing her actual name.
    • Also provides a straight example by calling Gentoku beardo and being called potato in return.
  • Amnesiac Dissonance: The loss of his memories turned him from a kindhearted farmer to a Psychopathic Manchild with an odd obsession with internet idols. Subverted in that he was faking, and trying unsuccessfully to alienate the Three Crows so that they wouldn't follow him to their deaths.
  • Anti-Villain: He's a battle hungry Rider who wants to defeat Build and Cross-Z and claim their FullBottles. However, he is against hurting innocent civilians and even tells Yoshiko not to send any Smash monsters to wreck havoc. He even goes as far to hijack a TV studio in Touto to broadcast a message of his intentions and urges all Touto civilians to stay home where they'll be safe. He's ultimately less of a villain and more of an enemy soldier.
  • Authority Equals Asskicking: He is the leader of the Hokuto Three Crows and he can defeat an ordinary Hazard Smash with one punch powered by the Helicopter FullBottle.
  • Bad Liar: The Three Crows don't buy his amnesia story for a moment, and they're right to do so.
  • Bash Brothers: He slowly becomes this with Sento after joining Team Build to the extent that it seems the days of Ryuga's partnership with Sento have passed, though he quickly shifts and forms a similar duo with Gentoku ultimately instead.
    • Later on, he and Gentoku form a similar duo as Sento and Ryuga. Interestingly enough, Kazumi is usually the sane one of them two.
  • Benevolent Boss: To the Three Crows. He genuinely cares about them and doesn't want them to hurt themselves doing anything stupid. He was one to them before his memory loss as well, back when they were workers on his farm before the Sky Wall ruined Hokuto's agriculture and with it their livelihood. While Kazumi claims not to remember this, the Crows do, and repay his sacrifices with their Undying Loyalty.
  • Blood Knight: To the point that he'd even attack his own men if there was a chance it would get him a good brawl. According to Sento, this is a side effect of transforming with the Sclash Driver, as the user is subjected to the belt's dangerous Nebula Gas influence. It's essentially the same as having their aggression cranked up thanks to Pandora's Box.
  • The Cameo: He debuts after Heisei Generations Final: Build & Ex-Aid with Legend Riders, which chronologically takes place after #14 and before his introduction in the series. During the movie, he steals the Phoenix and Robot Fullbottles from Build. In the series, he appears for a brief moment defeating Guardians at the end of #16.
  • Cold Ham: He has this sort of swagger that comes without exaggerated gestures or even rising his voice. He can swing the other way after transforming.
  • Conditioned to Accept Horror: #21 gives a reason for why Kazumi is coldly professional when it comes to everything else but fighting. He has seen people die in front of him already and is accustomed to the harsh reality of the war he is a weapon of. His not-so-visible reaction to Aoba's death shows that it's not complete.
  • Died in Your Arms Tonight: Misora holds him as he is dying in #47.
  • Enemy Mine: With Sento and Ryuga, starting from #23. Separately, they don't have many chances against Seito's forces and considering they are pretty close to being counterparts on their respective sides, it's a logical conclusion to join forces. It's a while before it fully takes, but #24 sees him seal the deal with Sento.
  • Evil Knock Off: Though "evil" is a rather strong word. Like Sento, he's lost all his memories of his previous life and similar to Banjo, he enjoys a good fight. To further the parallels, he was handpicked by Blood Stalk to be a Kamen Rider, just like they were.
  • Feet-First Introduction: He first appears in the show proper with multiple Touto Guardians surrounding his feet. As the camera shows his full body, it’s shown that he has ripped a hole in the Sky Wall and decimated Touto’s forces guarding Touto’s perimeter connecting it to Hokuto.
  • First-Name Basis: He's the only member of Team Build to refer to Banjo as Ryuga.
  • Good Angel, Bad Angel In #46, he sees Misora's towel draped across the back of a chair and mentally debates using it to dab the sweat off his face. His good angel (depicted as Kazumi in chains) says that if he sinks that low he has no right to call himself an idol fan, while his bad angel (Kazumi in summer clothing sitting in a deck chair with the Mii-tan body pillow) says that she shouldn't have left it there if she didn't want people using it. His bad side wins...and then it turns out to be Gentoku's towel rather than Misora's.
  • In-Series Nickname: He wants to be called "Kazumin" by the other characters.
  • Instant Expert: At best, he's had his Sclash Driver for a couple of weeks longer than Banjo has had his, but boasts a robust amount of skill and cunning while using it in tandem with the bottles he has access to, even managing to outmaneuver Sento who designed his belt and has been a Rider for months.
  • Just Following Orders: Unlike Chaser and Necrom who started off as willingly as villains before becoming heroes, Satawari isn't evil at all, and only comes into conflict with Sento because he's ordered to. So once his boss gets captured, he practically jumps at the opportunity to start helping Sento and Ryuga.
  • Jerk with a Heart of Gold: He is morose Shell-Shocked Veteran, whose life philosophy is largely determined by War Is Hell. Well, half of it. The other half is made from his belief in importance of family, friendship and kindness. He cares about the Three Crows greatly, but he is determined not to show it when they are looking.
  • Killed Off for Real: He dies fighting Evolto's mimics in #47 and he goes down swinging.
  • The Leader: He's the leader of the Smash group Hokuto Three Crows and has the rank of captain.
  • Meaningful Name: Grease refers to both his high agility as a Rider and the fact that his infatuation with Misora is viewed as rather skeevy by everyone in the cast.
  • Nice Job Breaking It, Hero: Sento originally made the Blizzard Knuckle as a safe power-up for him, to increase his Hazard Level to manageable levels. However in his own hastiness to get stronger he runs off to get additional doses of Nebula Gas TWICE before it could be given to him. By the time he receives the Knuckle, it was too late as the additional power it provides would now be too much for his body to handle, resulting in his own death after he eventually gets forced to use it to transform.
  • No Sense of Direction: He berates Three Crows for leaving him behind, stating they know he gets lost easily.
  • Not in This for Your Revolution: Even after joining the heroes at nascita, he's only really focused on saving Hokuto, which causes nearly back out a couple times. Eventually though, he admits that Sento's "love and peace" ideals have "infected" him.
  • Not So Stoic: He's introduced as being a calm, stoic Blood Knight and a fast thinker who cares nothing for his teammates. He almost immediately reveals the first chink in his armor: he's an enormous Mii-tan Fanboy, to the point where he refuses to let her come to harm and just seeing her causes him to freeze up and make critical mistakes. He's also steadily revealed to care much more about the well-being of his teammates than he wants to admit.
  • Punch-Clock Villain: He's not a supervillain so much as an enemy soldier who's only fighting for his country for the sake of his loved ones. Thus he's only Sento and Banjo's enemy so long as their countries are at war. The moment Hokuto is invaded by Seito and the war between Hokuto and Touto is technically over, he's more than happy to join forces with the heroes.
  • Shoot the Shaggy Dog: Kazumi sacrificed everything he had and subjected himself to Nebula Gas experimentation with a dangerous Driver to protect and provide for his friends in Hokuto. Within ten episodes, his three closest friends are dead, and their home has been taken over by a hostile nation while they were away.
  • Single-Target Sexuality: To Misora, and tries to get to get her to recuperate said feelings to no avail. At least until New World:Grease.
  • Tranquil Fury: His bloodlust isn't as pronounced as Banjo's while they use their Sclash Drivers, but it's of comparable, if not greater, intensity.
  • Tsundere: Type A towards most of the people he cares about. He manages to hide it very well with Three Crows. Even when they lifted him out of excitement, he shows no sign of enjoyment and only ordering them to drop him. They do so when they see Sento and Ryuga and even then it's not entirely voluntary.

Tropes exclusive to him as Kamen Rider Grease
Tsubureru! Nagareru! Afurederu!note  Robot in Grease! Buraa!
Click here to see Grease Blizzard 
Are you Ready? Gekitō Shinka! Grease Blizzard! Gakigakigakigaki Gaki~n!
Click here to see Grease Perfect Kingdom 
Are you Ready? Farmers Festival! Grease Perfect! Gakin! Gokin! Gakon! Docking!

  • Badass Normal: Grease doesn't have an endless fountain of new power-ups like Build or a massive Hazard Level like Cross-Z or Rogue, nor does he have their deep ties to the backstory that drives the show's central conflict. Stalk isn't interested in promoting his growth as an adversary. He's just an ordinary farmer who became a soldier to protect his loved ones, and that's exactly what he does, no matter how great the odds stacked against him may be.
  • Blade Below the Shoulder: Grease Perfect Kingdom is armed with two, based on the Stag Smash.
  • Bling of War: Grease's color scheme is gold.
  • Can't Catch Up: Grease spends most of the middle half of the show lagging badly behind everyone else, with all of Seito's forces being as strong as him or stronger. In the last quarter, aware of his status as the weakest of the four main Riders, he starts taking increasingly desperate measures to avert this. It somewhat backfires on him, as his drastic measures rendered the actual upgrade Sento had been building for him a fatal one if used.
  • Deadly Rotary Fan: Can summon an energy rotor blade thanks to the Helicopter FullBottle.
  • Deadly Upgrade: Kazumi starts chaining them in the show's last act, with two separate Nebula Gas infusions in episodes 40 and 44, followed by using the Blizzard Knuckle with the Build Driver in #46 to acquire the Grease Blizzard form, all of which have the potential to kill him. Sento even says that if he uses Grease Blizzard with his elevated Hazard Level, it'll almost certainly kill him. And it does. Thankfully, the world reset seems to have fixed this problem and thus he's able to use Grease Blizzard without issue.
  • Dual Wielding: He eventually gets a second Twin Breaker, which blends well with his upgraded Hazard Level.
  • 11th-Hour Superpower: He gains Grease Blizzard during the final battle with Evolto, two episodes before the end of the series.
  • Everything Fades: The Eraser FullBottle can be used to produce this effect as a method of exiting stage left.
  • Evil Knockoff: Grease's Sclash Driver was produced by Namba Heavy Industries using the data stolen from Sento's lab. Unlike many knockoffs, though, his is exactly the same as the one Sento made, just with a different choice of Sclashjelly.
  • Finishing Move:
    • Scrap Finish: Either a Rider Punch or Rider Kick, the latter using the Machine Pack Shoulders for rocket propulsion. Ganbarizing presents an alternate version of this finisher where Grease instead creates four robotic drones that latch onto the enemy and explode.
    • The Twin Breaker possesses hundreds of possible Single Finish and Twin Finish attacks, depending on its mode and which Fullbottles and/or Sclashjellies are inserted. The Robot Sclashjelly generally adds a neutral effect that just amplifies whatever the other bottle in the combination is, or amplifies the weapon's basic function if used alone. Once he starts Dual Wielding them, he's shown to be capable of even more potential finishers.
    • Grease Blizzard:
      • Glacial Attack: Grease creates a large Variable Ice construct of the GBZ Demolition One that spins before he grabs the enemy with it and crushes them.
      • Glacial Finish: Grease produces ice from each of the GBZ Ice Pack Shoulder in order to propel himself forward and performs a flying kick covered in light blue energy. The kick freezes enemy upon contact and destroy them into mist.
    • Grease Perfect Kingdom:
      • Stag Slash: Grease charges the blades on his arms with blue energy before delivering a series of slashes.
      • Owl Speed: Grease flies into the air and rams into the enemy four ties in quick succession
      • Castle Cannon: Grease creates energy constructs of the Castle Smash's Ground Ramparts and uses them to fire two large, red lasers
      • Perfect Kingdom Finish: Grease jumps into the air as images of the Three Hokuto Crows performing flying kicks appear alongside him. The three images then combine with Grease in the form of yellow, blue, and red chains of energy. The energy converges into a colorful vortex of energy on Grease's foot as he delivers a powerful flying kick to the opponent.
  • An Ice Person: As Grease Blizzard.
  • Jack-of-All-Stats: Like Cross-Z Charge, the Sclash Driver grants Grease vastly more powerful all-around abilities than the Build Driver. Unlike Cross-Z Charge, he appears to have read the instruction manual and spent time practicing with the Driver before going out to fight, allowing Grease to take much better advantage of the special abilities it grants him. He also starts with the highest Hazard Level of anyone, though it's noted immediately that this advantage won't last, and indeed he swiftly falls into being the weakest of the four main Riders. Played with however as Kazumi has stated that being in multiple fights has risen his Hazard Level quite a bit, so he can still try and keep up with the other rider's rising power ups.
  • Luckily, My Shield Will Protect Me: Using the Castle Fullbottle with his belt allows him to manifest incredibly durable shields... made out of grease.
  • Motif Merger: As Grease Blizzard, at least his right shoulder armor is adorned with the symbols of the Castle, Stag, and Owl FullBottles, the latter two in the foreground.Grease Perfect Kingdom also takes the designs and the armaments of the Three Hokuto Crows into a single suit
  • Not Quite Flight: The boosters on his shoulders can boost his vertical and horizontal agility in small bursts, but he needs to use other bottles to achieve real flight capabilities.
  • Overclocking Attack: Using a Twin Finish and a Scrap Finish simultaneously causes severe backlash, overloading his belt and knocking him out of his transformation.
  • Primary-Color Champion: Grease Perfect Kingdom prominently displays red, yellow, and blue; the colors of the Hokuto Three Crows.
  • Simple, yet Awesome: Using the Dragon Sclashjelly gives him two Twin Breakers. It’s not much, but two blaster/stabbing weapons rather than one make a surprising difference.
  • Swiss Army Weapon: Uses the Twin Breaker which has a long range Beam Mode and a close range Attack Mode. With the Dragon Sclashjelly, he gets a second one.
  • Super Mode:
    • Kamen Rider Grease Blizzard, achieved using the Blizzard Knuckle and the North Blizzard Bottle in a Build Driver. It originally killed him to use it, but after the world reset he's able to use it without issue.
    • Grease Perfect Kingdom, which is even stronger than Blizzard and uses the power of the Three Crows.
  • Technician Versus Performer: Grease strikes the middle ground between Build and Cross-Z. He doesn't have Build's dozens of options in battle, but he's got better fighting skills and starts with a higher Hazard Level. He doesn't have Cross-Z's ever-escalating Hazard Level, but he has better control over his suit and makes noticeably greater use of secondary bottles in situations where brute force isn't enough.
  • The Juggernaut: In #22, it was shown that Grease, unlike Cross-Z Charge or Build, is extremely durable, and was able to take attacks continuously from a variety of Best Match forms and finishing moves, and didn't seem worse for wear. The only reason he apparently lost was due to Sento using the Hazard Trigger, but even that lasted until nightfall, and it was only when Sento lost control and whipped out the big guns that Grease was forced out of his transformation.
    • Zig-zagged in the later parts of the series, even when the weakest of the Riders, this is notable as he still manages to take damage from Evol or MadRogue and still keep himself in the game by sheer endurance.
    • Played straight as Grease Blizzard, which clearly could take a beating from the Hokuto Crow mimics. Kazumi only died because the Knuckle pushed him way too far past his limit. After the World Reset, that problem is taken care of and it's the first thing that's actually able to put a dent in Metal Build, who's himself this trope, and even withstands a finisher from him without losing transformation. It takes a finisher and being thrown out a skyscraper by the much stronger Phantom Build to knock him out of transformation, and even then he survives and is still in fighting shape once he upgrades to the even stronger Perfect Kingdom.
  • Villain: Exit, Stage Left: Eraser and Helicopter are both used for beating retreats as often as they are for battle.

    Gentoku Himuro/Kamen Rider Rogue 

Gentoku Himuro

Portrayed by: Kensei Mikami (live), Jun Watanabe (suit)
Gentoku during his time at Seito
Gentoku after his Heel–Face Turn

"I will sacrifice you for the greater good!"

The head of the Touto Institute of Advanced Matter Physics as well as an aide and son to the Prime Minister of Touto, Gentoku oversees the research on the Pandora's Box. Was present at the Skywall Tragedy 10 years ago, and thus was also affected by its energies, increasing his aggression.

He is the true identity of Night Rogue, one of the creators of Faust. After being expelled from Touto, he becomes a servant of Seito, using the Crocodile Crack Bottle with the Sclash Driver to transform into Kamen Rider Rogue.

Tropes that apply to him in general

  • Ain't Too Proud to Beg: Not that Utsumi was actually going to keep his promise to make him a Rider at all.
    • Desperate to save his father, he calls Sento of all people to plead with him for help.
  • Ambiguously Evil: In his earliest appearances, where he's obviously sinister but allegedly working for a good cause. It doesn't take long for his true nature to come out, and the trailer at the end of #6 makes obvious what #7 confirms: he's Night Rogue, and his evil is anything but ambiguous. This trope is reapplied when he becomes Kamen Rider Rogue until his true intentions are later revealed.
  • Anti-Villain: Turns into this after becoming Kamen Rider Rogue. The experiments and Nebula Gas injections that helped raised his Hazard Level also nullified the Pandora Box's Hate Plague, but he kept going through with his goal of reunifying the country by force, not so that he could be the one ruling, but to hand it over to his father, who would make sure the country was run in the best interests of its citizens.
    • Anti-Hero: Becomes one after his Heel–Face Turn - while he's still willing to get his hands dirty, he's firmly on the side of the heroes.
  • Bad Guys Do the Dirty Work: Invoked. Knowing that his father's pacifism is a liability to unify the country, Gentoku founded Faust and mastermind the war to get the Pandora Box and unify the country before giving its leadership to his father, of all people, knowing full well that it would cost his reputation.
  • Be Careful What You Wish For: He wanted to become a Kamen Rider. It wasn't a very pleasant process, to say the least.
  • Break the Haughty: The torturous experience that led Gentoku to become Kamen Rider Rogue was good for him in at least one way: he admits during his representative battle with Sento that it was his pride as much as the limits of his suit that had brought about his previous failures and kept him too weak to handle his problems himself. It was only after abandoning his vanity that he was able to achieve his true potential.
  • Broken Faceplate: In #48, Gentoku as Rogue received a huge wallop from Evolto in his ultimate form, damaging his helmet's Hard Jelly Eyes.
  • The Comically Serious: From his Rummage Sale Reject outfits and his Fun T-Shirt sets he's one of the sources of Team Build's laugh out loud moments, all while keeping a straight face.
  • Cruel Mercy: He spares Sento and Ryuga after defeating them because he wants them to suffer like he did.
  • Death Equals Redemption: Since his Heel–Face Turn he spent the rest of the series questioning himself on whether he has lived up to his father's expectations. With Kazumi's forgiveness and the citizens' cheering him in his final moments, he eventually received his answer.
  • Determinator: Even when heavily outclassed by Evolto he still goes for a full assault in order to damage the latter's Evol Trigger. A few punches and a Crack Up Finish later, he succeeded.
  • Died in Your Arms Tonight: When his father goes down Taking the Bullet for him, Gentoku is dazed by shock for a moment before he realizes what happened and takes him into his arms to hold him as he is dying.
  • Dying Moment of Awesome: Dies after going for a full assault towards Evolto in order to damage his Evol Trigger in #48. He succeeded at doing so, stunning Evolto and giving an opening for Sento and Ryuga to finish the rest.
  • Enemy Mine: He joins forces with Sento and Kazumi in #35. They all know just how underpowered they are against Evol, especially once he acquires both his driver and ultimate vessel.
  • Even Evil Has Loved Ones: He's genuinely worried when his father suffers a major heart attack during #10, but that is immediately superseded by how giddy he is that this happenstance makes him the de facto leader of Touto. This can also be seen as his original kinder nature briefly pushing through what the Pandora Box's Hate Plague did to him.
    • His shocked and heartbroken reaction to his father's death brings this in full force.
  • Even Evil Has Standards: His efforts to undermine Namba's plans for world domination from the inside are this at first before eventually growing into a full-fledged Heel–Face Turn.
    • During #31 he uses a grapple with Sento to secretly explain that Mido is actually Namba in disguise and that he only wanted to use Pandora's Box as a deterrent while Namba has more sinister plans for it, imploring him to steal the box before it can be opened. He tellingly even checks during the grapple several times to see if either of the fanatically loyal to Namba Kaisers can hear him.
    • #32 has him risk having his Explosive Leash triggered to save Kazumi's workers in Hokuto, showing that threatening their lives to try and force Kazumi to betray Touto is also beyond his standards.
  • Evil Makeover: Seemingly eviler makeover, rather, but upon being kicked out of Touto, Gentoku grows his hair out and starts wearing a new black and red outfit (Seito's colors).
  • Explosive Leash: Namba implants one when he starts working for Seito: although it delivers electrical shocks rather than exploding, it can still kill him if used at full strength. Sento eventually disarms the chip by changing the signal, just in time for Gentoku's Heel–Face Turn.
  • First-Episode Twist: The end of #6 reveals his identity as Night Rogue after considerable teasing beforehand. It becomes impossible to talk about Gentoku's further actions without mentioning it.
  • Foil: To Sento, who gets his power from holding onto his identity and the people close to him. He is also nearly deathly afraid of losing both. This doesn't bother Gentoku at all as he doesn't care about anyone but himself and discarded everything but his name and some of his personality traits to become Kamen Rider Rogue. It's also in the fact that Gentoku thinks of himself as hero fighting to unite the country. This is reflected by him taking the title of "Kamen Rider" for himself. Sento denies being a hero and just wants people to be safe regardless of who they are or which region they live in. He got the title from people of Touto.
  • Fun T-Shirt: After his Heel–Face Turn, he starts wearing these along with a Rummage Sale Reject outfit. Later, he just wears the shirt underneath a biker jacket and unzips it as a response to something (to mixed results).
  • Good Counterpart: To Utsumi. Both are Touto Government officials who are actually affiliated with Faust, and serve a father (or in Utsumi's case, a father figure). However, Gentoku is genuinely loyal to his father, and is willing to sacrifice his reputation to put the country in his father's hands, whereas Utsumi was willing to work with Namba's killer the second he had a chance. Furthermore, Gentoku's mental state improved drastically upon becoming a Kamen Rider, whereas Utsumi's...going to end up in a mental institution by the end of the series if he's lucky. And Gentoku is willing to do the right things in order to atone for his previous actions, while Utsumi is starting to do all sorts of wrong things and not feel any regret for his actions (although it is later revealed that Utsumi was just pretending to join Evolto so that he could get revenge for Namba).
  • Handsome Lech: When Sawa asks him about the Smash and Kamen Rider, he responds by propositioning her to discuss them in a hotel all night long. Predictably he gets shot down.
    • The final episode indicates it's an aspect of his warped personality as his and Sawa's selves in the new world meet up again almost exactly like their first appearance, but this Gentoku is far more professional, without even so much as a flirt towards Sawa.
  • Heel–Face Turn: #30-33 showcase his steady return back to his original kindhearted self, with his heightened Hazard Level thanks to the Sclash Driver having broken the spell the Pandora Box once held him under. And he now joins the heroes as one of the main Riders in the fight against Evolto.
  • Heroic BSoD: For all that the events detailed under Humiliation Conga were traumatic to Gentoku, the death of his father hits him harder than all of them combined. He's seen sitting dazed in the wreckage of Touto days later, utterly shell-shocked.
  • Hidden Depths: The ROGUE mini-series brings up some interesting details:
    • Gentoku used to like to relax by eating sweets and singing at karaoke bars. His conversation with the receptionist even suggests that he's been doing so for a very long time.
    • He has knowledge of European classical literature. When Soichi brings up Faust's Deal with the Devil, Gentoku answers that he lost his soul in exchange and that Soichi doesn't have as much power as Mephistopheles.
    • His father was right. Gentoku apparently really was a good, amiable person before being corrupted by the Pandora Box.
      • One's that Played for Laughs, but it turns out that he has terrible sense in casual wear, to the horror of everyone at nascita .
  • Humiliation Conga: The day his father recovered enough to lead Touto again lead to a chain of events that could be called the worst few days of Gentoku Himuro's life. First his father, who knows he was the leader of Faust, recovers and disowns/exiles him leaving him with no power and no backup. Then he gets his ass kicked by the heroes on his way out leaving him painfully aware that he's outclassed by everyone at this point. Then when he corners Utsumi he's forced to beg for power that his old lackey doesn't even give him, leaving him chained up in a cage screaming for answers as to why he can't be the one. It works out better for him than if he hadn't done anything, since he becomes the monstrously powerful Kamen Rider Rogue, but his newfound power still isn't quite enough to defeat Sento.
    • It turns out the conga line just stalled for a bit. For one, it turns out that raising his Hazard Level has also broken him free of the influence of the Pandora Box. While this does mean that he's good again, it also means that he has to bear the guilt of all of his sins. And he can't stop because Namba made sure to install an Explosive Leash onto him in order to force him into doing their bidding, up to forcing him to kidnap his father so that Evolto can have a bargaining tool to get back his Evol Driver. Then, when he finally finds a way to disable his kill chip, he ends up failing to stop Evolto, gets curb-stomped by Kamen Rider Evol's debut, and watches as Taizan ends up Taking the Bullet for him.
  • Jerkass: Kidnapping Katsuragi's mother and then forcing her to exchange information for her son's heartfelt will, only for it to be a complete lie was a pretty asshole move on his part. It takes numerous episodes and getting some sense beat into him repeatedly to finally get better.
  • Kicked Upstairs: As shown in the ROGUE mini-series, his status as the head of the Touto Institute of Advanced Matter Physics in spite of his overt lack of scientific expertise was given to him by his father to keep him out of Touto's politics as he was wary of how the light of Pandora's Box warped his mind. Thanks to Katsuragi, Gentoku was able to use this to advantage, using the institute's nigh-limitless access to the artifact to aid in Faust's research.
  • Klingon Promotion: He managed to snag the privilege of being Kamen Rider Rogue by outlasting and sometimes even murdering the other candidates for it who were higher up in the queue.
  • Manchild: It turns out, underneath his Pandora's Box affliction, this is his true nature. He's pretty mature and serious most of the time. But that aside? He hates green peppers, can't buy a train ticket by himself, sleeps with a night light and has the fashion sense of a sack of mouldy ham. Sento even straight-up calls him a baby in the recap of #41.
  • Meaningful Name: His given name is a homonym for "illusion/mirage". More directly to his secret identity, whenever his full name is said, the last syllable of his last name and first syllable of his given name are together pronounced as "rogue".
  • My God, What Have I Done?: Later in the series, Gentoku has clearly shown to feel regret for his previous actions, which prompts him to join the heroes side and to set things right.
  • Not So Above It All: His fashion sense and love of karaoke show that he's not exactly the most serious character, despite his Shell-Shocked Veteran status.
  • Plot-Powered Stamina: Played for Laughs example. Despite running at full speed, as mentioned immediately below under Rich in Dollars, Poor in Sense, he's still only mildly winded from the long sprint, and can match Evol Cobra with Prime Rogue while being none the worse for wear.
  • Rich in Dollars, Poor in Sense: Downplayed. #41 reveals that, despite his original position and knowing certain places around town, he still doesn't know to buy a train ticket. So, in Prime Rogue when Misora demands he meet her at a department store in another part of town (in a semi-vain attempt to fix his Rummage Sale Reject status), he runs at full speed all the way (with train noises) from Nascita to that store, which has a distance that takes 10 minutes by train. Even the initially sheltered Misora is shocked at him running that far and not bothering to learn how to use the train.
  • Rule of Symbolism: After his metaphorical death and rebirth into Kamen Rider Rogue, Phoenix becomes Gentoku's favorite transportation Fullbottle.
  • Rummage Sale Reject: After completing his Heel–Face Turn, his taste in civilian clothing is revealed to be... questionable.
  • Sanity Slippage: He's... not all there after becoming Kamen Rider Rogue, or so it seems. He's actually more there than ever, no longer afflicted by the curse of the Pandora Box. He is a Shellshocked Veteran, but definitely more in possession of his marbles than before.
  • Selective Obliviousness: Zig-zagged. He's firmly aware that the war-hungry nature of the Hokuto and Seito leaders is a result of Pandora's Box increasing their aggression. However, he completely fails to notice his own personality change for ten years until his father points it out to him. After the confrontation, he's self-aware enough to admit he's been corrupted, but not enough to want to stop his plans to take over Japan or find a cure.
  • Shell-Shocked Veteran: A combination of what he had to endure to become Kamen Rider Rogue, being cured of the influence of Pandora's Box, realizing just what he did under its influence and being made into Seito's attack dog under threat of threat of death have made him into cynical stoic with a Thousand-Yard Stare. He only starts getting better after his official Heel–Face Turn.
  • Significant Wardrobe Shift: Goes through this three times throughout the course of the series.
    • He starts off wearing the Touto Government's uniform. After being banished from Touto and joining Seito, he wears a customized uniform of their colors (red & black), signifying his defection.
    • After his Heel–Face Turn, he goes to wearing his casuals from not needing to wear a uniform anymore. Said casuals being Rummage Sale Rejects he actually deems as normal clothing.
    • After the events of Prime Rogue, he retains his Fun T-Shirt underneath a black leather jacket, given to him as a memento from a kid he saved after he taught the boy to move on from his father's passing as he did himself.
  • The Shadow Knows: When he finally dies fighting Evolto, he falls to his knees untransformed, wondering if he made his father proud even a little bit... but during the scene, his shadow is still the silhouette of Kamen Rider Rogue, showing that he did indeed go down a hero.
  • Training from Hell: Becoming Kamen Rider Rogue was this for him, courtesy of none other than Stalk. It involved him constantly trying to transform with the Crocodile Crack Bottle and a Sclash Driver that he was too weak to use while getting beaten to a pulp by Guardians until his emotions hit a breaking point and caused his Hazard Level to shoot up to at least the requisite 4.0 to use a Sclash Driver.
  • Took a Level in Badass: He mops the floor with all three previous Riders after becoming Kamen Rider Rogue. The upgrade improves not just his physical performance, but also his skills as a tactician, as he's able to casually turn RabbitTank Hazard's berserker traits to his advantage. He's even the first person to force Blood Stalk to drop his transformation, although not before Banjo softened him up beforehand.
  • Tyrant Takes the Helm: After his father's stroke, he's made the acting leader of Touto. He becomes leader again after Stalk attacks his father.
  • Ultimate Job Security: An absolutely infuriating example, but even though his father knows he's Faust's leader and a criminal, Gentoku is still Touto's leader due to Hokuto declaring war and Taizan not being fit enough to lead again. That said, the warranty on his job security runs out with #20, where Taizan comes back and this time wastes no time both disowning Gentoku and running him out of Touto.
  • Used to Be a Sweet Kid: According to his father, he used to a gentle kid before the Sky Wall Incident. This is also one of the reasons why his father refused to think about how much Gentoku changed in the following years up until early into the story. After his Heel–Face Turn we get to see that Gentoku in his normal state is a lovable goofball with horrendous fashion sense proving his father right.
  • Villain Has a Point: He's in no way a good person, even disregarding the whole terrorist thing, but he does have a point the other two factions Japan has been divided into are looking for a Pretext for War due to their leaders being corrupted by Pandora's Box's Hate Plague. Of course, that in no way justifies stealing the Box to intentionally provoke said war.
  • Villain with Good Publicity: As far as the public knows, he's the good second in command of the country, who filled in for his father after his stroke and destroyed Faust. By #48, he dies as a hero with good publicity.
  • Walking Spoiler: It's impossible to discuss Gentoku's actions in any significant capacity without talking about his secret identity and eventual defection to Seito.
  • Would Hit a Girl: He tried to shoot Misora to keep her from using her powers on him again in #25.

Tropes exclusive to him as Kamen Rider Rogue
Wareru! Kuwareru! Kudakechiru!note  Crocodile in Rogue! Oraa! (scream)
Click here to see Prime Rogue 
Are you Ready? Taigi Bansei!note  Prime Rogue! Doryadoryadoryadoryadoryadorya Doryaa!
  • Abnormal Ammo: As serious as he appears, his Nebula Steam Gun allows him to blast out some fairly ludicrous projectiles depending on the bottles he uses with it including diamonds, a crocodile made out of energy, and even himself.
  • Agent Peacock: He boasts the flashiest outfit worn by a villain in the first half of the show that possesses shiny alloys, bright race lines, and white gloves.
    • Played even more straight as Prime Rogue, which adds golden highlights and a cape to the ensemble.
  • Antagonist Abilities: Subverted, he keeps his Nebula Steam Gun and its power to retreat from battle with a smokescreen even after his Heel–Face Turn.
  • Authority Equals Asskicking: The leader of Seito's forces, and capable of curbstomping RabbitTank Hazard. To establish his badass cred, he's introduced to the viewer dragging the corpse of a Hokuto Guardian with his hand knuckle deep in its face.
  • Badass Cape: Gains a white one as Kamen Rider Prime Rogue.
  • Can't Catch Up: Despite being by far the most powerful rider when he was introduced, he is eventually revealed to have fallen significantly behind as unlike the others who were engaged in constant battles that elevated their Hazard Levels, Rogue took on a more static role of watchdog for Utsumi. When he fights Grease midway through the series he is handly defeated. He eventually overcomes this but still lags behind the top tier. He also never gets to use Prime Rogue in the series as the bottle is damaged in its first use. He regains access to it in the post-series media but by then everyone else has a final form that surpasses it.
  • Combat Pragmatist: Because his suit has a higher capacity to do so, he's all too willing to dish out Finishing Move after Finishing Move in quick intervals to achieve victory.
  • Cool Gun: The Nebula Steam Gun. Essentially a repainted version of the Transteam Gun. When combined with the Steam Blade, it becomes the Nebula Steam Rifle.
  • The Dragon: In a cruel twist of irony, he winds up being Stalk's in an inversion of their original relationship.
  • Evil Knockoff: His Nebula Steam Gun was designed by Kaisei Mogami as an improvement on Katsuragi's original Transteam Gun, while like Grease his Sclash Driver was built by Namba Heavy Industries using data stolen from Sento. His Crocodile Crack Fullbottle comes off as an evil knockoff of the regular bottles as well, with a new "broken" aesthetic.
    • Funnily enough, after he becomes good, he gets his own evil knock-off in the form of Kamen Rider Mad Rogue.
  • Fashionable Asymmetry: In addition to the asymmetrical Sclash Driver, Rogue's mask is designed to resemble a crocodile chomping on his head from beneath, giving the chin guard an eye-like gem on its right side.
  • Feet-First Introduction: Like Grease, he makes one of these for his debut, dragging the wreckage of a Guardian behind him as he slowly walks into Tajimi's office.
  • Finishing Move:
    • Crack Up Finish: Rogue leaps at the enemy and performs a scissor kick, with projections of a crocodile's mouth forming around his legs as he does so.
    • Nebula Steam Gun: Using the Nebula Steam Gun, he fires a large projection of a crocodile mouth via the Funky Break, or he can use a variety of Fullbottle powers through the Funky Attack.
    • Charge/Discharge Crush: Using a FullBottle directly in his Sclash Driver, Rogue can conjure a variety of powers.
    • Prime Scrap Break: As Prime Rogue, he delivers an upgraded, golden version of the Crack Up Finish.
  • Golden Super Mode: His Kamen Rider Prime Rogue form from his HBV is a more subdued example as it replaces the jagged white cracks on his original suit with gentle golden curves. While originally a Hyper Battle exclusive form, it eventually came into the main canon as his true Super Mode.
  • Hell Is That Noise: Unlike the other Rider's whose transformation sounds are more upbeat and generally use more upbeat (if sometimes harsh) sounding songs, Rogue's is more or less a horror movie track complete with a woman screaming.
  • Made of Diamond: Ironically, considering the fragile sticker on the back of his head. Rogue, like Grease, is phenomenally durable, if not even more so: he's so tough in fact that nothing short of the berserk Hazard Trigger-enhanced Build can even make him flinch, simply no-selling everything else that all three Riders have to throw at him. While RabbitRabbit can harm him, Rogue still takes direct hits from four consecutive finishers from it, in its debut episode and with its insert song playing full blast, just as a warmup. Using the Diamond Fullbottle makes him even tougher to the point where even RabbitRabbit can do nothing at all to him. It takes a battle that lasts all night and well into the next day, taking up nearly half an hour of screentime spread over two episodes, and another round of eating multiple consecutive finishers from another form debut with a Theme Music Power-Up to actually bring him down. Even after all that, he's back on his feet a minute later and in good enough condition to walk away without so much as a limp. It isn't until the Big Bad gaining his power-up does his toughness begin to fail and even then, he could still take a Curb-Stomp Battle and keep trucking.
  • Never Smile at a Crocodile: Has this as his Animal Motif.
  • Purple Is Powerful: Where the previous year's evil Rider just had purple highlights on his suit, Rogue's is almost entirely purple.
  • Shout-Out: Combined with Incredibly Lame Pun, his transformation jingle is similar to the iconic foreboding track of Jaws fame and his metamorphosis is capped off with crocodile jaw-like construction equipment smashing him out of a beaker.
  • Sixth Ranger: More or less fulfills this trope to a T as the series' fourth Rider after Build, Cross-Z, and Grease.

Café Nascita

    Soichi Isurugi (SPOILERS) 

Soichi Isurugi/Blood Stalk/Kamen Rider Evol

Portrayed by: Yasuyuki Maekawa (live), Tetsuo Kanao (voice)

The owner of nascita, the cafe where Sento and co. hide their base of operations. He helps out with occasional surveillance and generally acts as the Team Mom, offering his wise insight.

Prior to the show's events, Soichi was the astronaut who found Pandora Box on Mars 10 years ago and was subsequently possessed by the being known as Evolto. During the unveiling ceremony, Evolto touched the Box, attempting to destroy Earth as he had Mars but ended up initiating the Sky Wall Incident instead. Nine years later, he saved Misora from Faust, at which time he also stole a Pandora's Box panel, the Build Driver, and a number of Fullbottles. Soon after, Soichi encountered an amnesiac Sento in an alleyway and brought him in, encouraging him to use the Driver to become Kamen Rider Build. All of this was part of his schemes as Blood Stalk, using Sento and Misora to gather all twenty Fullbottles as well as Pandora's Box and both panels for himself. He continues to play a role that alternates in equal parts between mentor and antagonist, raising Sento and Banjo's Hazard Levels in pursuit of his goals: the ultimate vessel and the ultimate Driver. Soon after completing Banjo's growth, Evolto gains the Evol Driver and Evolbottles to transform into Kamen Rider Evol.

For tropes pertaining to when Evolto's not pretending to be Soichi, see his entry under Blood Stalk.

  • Actually Pretty Funny: When Soichi thinks he's made off with the bottles only to find out Sento tricked him into talking fakes. He's actually amused Sento got one over on him.
  • Ambiguously Human: At the end of #2, he twists a tablet computer into a back scratcher, and continues to demonstrate new abilities as the show progresses. Soichi claims his powers to be a result of having touched Pandora's Box on Mars, although that's not the whole story: his powers come from being possessed by Evolto.
  • Bitch in Sheep's Clothing: The friendly, slightly eccentric café owner is actually a double agent setting up "heroes" so he can take their research, possessed by an entity that seeks to obliterate all life on Earth.
  • Convenient Coma: After Evolto leaves his body to possess Ryuga, Soichi is left alive, but unconscious for the time being.
  • Cordon Bleugh Chef: His coffee is horrible. Even he himself hates it! This takes a darker turn once you realize that Evolto is an alien who has no clue how to make coffee and no reason to want to learn. In the new world where Evolto never existed however, his coffee is amazing.
  • Decoy Protagonist: It takes a good dozen-ish episodes for Soichi to reveal his true colors. Before then, he's one of Sento's most dependable allies.
  • Demonic Possession: Ever since he went to Mars, Soichi has been possessed by Evolto, the destroyer of Mars who seeks to do the same to Earth.
  • Evil Costume Switch: After the events of #14, Soichi stops wearing his glasses and starts wearing a lot more black.
  • Fighting from the Inside: The reason so many of the Best Matches are so silly is because Soichi fought back against his demonic passenger when Evolto asked him "name 30 things you like", followed by "name 30 ways I could kill those things". While at first his answers were things like tanks, gatling guns, rockets, and jets, once Soichi realized why Evolto was asking, he started providing random nonsense answers, and was able to do it for long enough that Evolto gave up and went with the silly bottles. He's also able to briefly wrest control of part of his body from Evolto, but never in a time or place where it particularly helps.
  • Gratuitous Italian: Sprinkles his dialog with various Italian phrases, often hamming them up for added effect.
  • In a Single Bound: Demonstrates this ability at the end of #14.
  • Kleptomaniac Hero: When saving Misora (or so he claims), he took a panel of Pandora's Box, the Build Driver, and the Rabbit and Tank Fullbottles from Faust. He later makes use of a cartoon-style Thief Bag when taking all of the spoils from nascita.
  • Mission Control: Provides Build with this.
  • Morality Pet: Misora is this to him, allegedly. In truth, she's only this to Soichi, not Evolto, who tries to kill her to kill Vernage.
  • Mysterious Past: Soichi's history is steadily revealed over the course of the show's first quarter.
  • No Sympathy: Played for Laughs with him making Sento pay for rent. Later played horrifyingly straight as he's been playing everyone (including his own daughter) the whole time without remorse, though he claims he did feel a little bad about it at times.
  • One-Hour Work Week: Soichi is never actually shown working at the cafe, as it's always shown either during off-hours or empty during business hours. Justified as he really doesn't have any customers, which is lampshaded in #13, but he claims that he keeps the place open out of sentimental value. Further justified as he supports himself with his other job (with Faust), and it's one that has a good reason to let him hang around the empty café (as Sento's and Misora's handler).
  • Purely Aesthetic Glasses: Which he ditches following The Reveal. Whether or not he genuinely needed them before being possessed is unknown.
  • The Reveal: Three big ones:
    • In #5, he gives a five-minute info dump when Sento confronts him on why he has a piece of Pandora's Box: he was the astronaut that originally found Pandora's Box, and then was suddenly compelled to grab it on Earth, though even he's not sure why. Faust blackmailed him to get Misora's power, until he rescued her and stole a bunch of their tech. He then found Sento and recognized another of Faust's victims, taking him in so he could use the stolen tech to defend them. And he kept all this from Sento because he knew it was a crazy story, so he waited until Sento was actively looking for answers.
    • #13-14 reveal that he's Blood Stalk and has been manipulating the group the entire time. When Misora wouldn't/couldn't purify Bottles for Faust any more, he "rescued" her and set Sento up as her heroic guardian to get her back on the job. Also, he switched to Namba's side.
    • #30 reveals that he's been possessed by Evolto this whole time.
  • Sincerest Form of Flattery: He works part-time at a competing cafe and tried to steal the recipe for one of their most popular blends to enrich his own restaurant. Although that's his cover for his more extracurricular activities.
  • Superpower Lottery: Whatever happened to Soichi on Mars, it granted him an enormous array of abilities ranging from enough strength to twist a tablet into a backscratcher and incredible leaping prowess to the ability to swap people's faces and erase memories with a touch. He eventually admits that the Blood Stalk suit is literally just a wardrobe to him: while some of the powers he uses come from the suit, nearly all of the major ones are actually his own, with the suit serving mostly as a fancy set of body armor that hides his true Hazard Level. The Evol Driver, in contrast, lets him bring out far more of his true power, and even its unearthly might is simply what he calls "Phase One".
  • Walking Spoiler: As the Big Bad of the show and a chessmaster par excellence, it's impossible to talk about Soichi, or rather Evolto, in any detail while pretending his early persona is all there is to him.

    Misora Isurugi 

Misora Isurugi/CD Lost Smash

Portrayed by: Kaho Takada (live), Sora Amamiya (voice only, as Vernage)

Soichi's daughter, who has a mysterious power that purifies Smash essences. She almost never leaves the lab in nascita's basement, but in her spare time she makes web videos under the name "Mii-tan" and occasionally calls on her viewers to send in tips to aid Build.

It was revealed that Misora gained the power to purify Smash essences in the wake of the Sky Wall Incident ten years ago, and consequently, fell into a coma for seven years. Prior to the series, she was captured by Faust for her powers, but her father saved her... except that was a lie. Misora found out what the Fullbottles were for and couldn't bring herself to make them anymore. Since her mental state is necessary to the process, Soichi engineered her "escape" as well as finding a "hero" to be Build. She would believe that she was helping for a good cause, and thus could resume bottle purification.

  • Berserk Button: When she threatens to cut you up if you wake her up after purifying a Fullbottle, she means it.
  • Clingy MacGuffin: The golden bracelet that's been stuck to Misora's left wrist ever since the Sky Wall went up is the source of her mysterious abilities. It's later found to contain the soul of Vernage, The queen of Mars, who shows Misora the destruction of the Martian civilization whenever her powers are used.
  • Dangerous Forbidden Technique: Purifying Smash essences without the aid of Sento's purifier machine is dramatically more exhausting, enough to leave Misora comatose for days if she attempts it.
  • Deadpan Snarker: Makes fun of Sento and Ryuga whenever she gets the chance.
  • Genki Girl: As "Mii-tan". Given her attitude the rest of the time, it's pretty clearly an act.
    • In #9, after Ryuga takes her into the city, she runs into the clothes shop squeeing in delight, meaning that not all of her attitude as "Mii-tan" is false.
  • Girls Love Stuffed Animals: Is occasionally seen holding her rabbit plushie in a few episodes.
  • Glass Cannon: When possessed by her bracelet, Misora becomes powerful enough to deconstruct parts of the Sky Wall and send Rogue and the Washio brothers flying through the gap before sealing it back up. That said, she's still an ordinary human with all the paper-thin defense against guns and superhuman monsters that implies, as she learns when she tries to invoke the bracelet's power a second time to help fight.
  • Healing Hands: Develops this power in #19. It comes with the same restrictions as purifying Fullbottles, namely exhaustion.
  • Hidden Depths: #9 suggest that not all of her attitude as "Mii-tan" is false as she runs into the clothes shop squeeing in delight after Ryuga takes her into the city.
  • Honor Before Reason: Upon learning of the power she displayed under her bracelet's influence, Misora wants to use it to help fight, which leads her to putting herself in harm's way.
  • I Just Want to Be Normal: She wants to be a normal girl that could go outside without having to worry about being kidnapped again.
  • Like Brother and Sister: She treats Sento and Banjo as big brother figures and they return the favor. Despite the playful banter and occasional tricks, she seems to admire both of the two and is willing to risk everything for them when it counts. In turn, both riders are extremely protective of her and will gladly pummel anything that dares bring her harm.
  • Limited-Use Magical Device: It's eventually revealed that the bracelet's power is finite, and starting to run out after all these years of usage. Late in the show, Misora willingly becomes the CD Lost Smash in an effort to juice it back up.
  • Locked Out of the Loop: Sento and Ryuga try to pull this on her in #14 regarding Blood Stalk's identity, only for her to figure it out by herself in the end of the next episode.
  • Mad Libs Catchphrase: She has one after she finishes purifying Fullbottle essences: "tired... sleepy..." the third thing added is the variable in the formula.
  • Mystical Waif: Misora's bracelet grants her a variety of superpowers, most prominently in the first act the ability to purify Smash essences to create Fullbottles. She develops new powers to replace it as this ability becomes irrelevant, all based around a supporting role. While she does have an offensive power, it's not under her control and extremely dangerous to use with her lack of armor.
  • No Social Skills: She rolls at her own pace and doesn't care if others can't keep up with her. Between spending 7 years in a coma after the Sky Wall incident and hiding from Faust, she never got the chance to develop any.
  • Pragmatic Hero: Upon developing Healing Hands, one of the very first things she does with it is go to the hospital and wake up Taizan Himuro from his coma so he can help stop the war.
  • Psychoactive Powers: Misora's mental state plays an important factor in her ability to purify bottles. Enough so that she couldn't produce them for Faust once she realized what they were using them for, which required Soichi to get more creative to make her produce the rest.
  • The Shut-In: She barely leaves the underground lab, due to hiding from Faust. The one time she does, though, she acts like a completely normal teenager, showing that her usual behavior is more a result of depression and isolation than her actual personality.
  • Ship Tease: Despite their bickering she is always looking out for Sento. Be it worrying about him dying or cheering him up when he’s down she will always be there for him. It is also hinted she may have feelings for him. Despite this, she ultimately chooses to recuperate Kazumi's feelings.
  • Sitcom Arch-Nemesis: Once Gentoku joins the team, he become this to Misora as his fashion sense disgusts her and even kick him out of the cafe!
  • Sleepy Head: Tends to tire out after using her powers to purify a bottle of Smash Essence. This was worse before Sento built a machine to utilize her power, as without it, she would fall into week-long comas.
  • Symbiotic Possession: Misora's bracelet is capable of possessing her, turning her eyes a supernatural shade of green and causing her to display powers that allow her to tear down sections of the Sky Wall as well as easily defeat the Washio brothers and Kamen Rider Rogue. This possessed identity says nothing but the word "Evolto" in its first appearance, but in its second introduces itself as Vernage, the queen of Mars, and subsequently explains that "Evolto" was the one who destroyed Mars with Pandora's Box. Misora doesn't mind, as the entity is protecting her and her friends, and never possesses her except when needed unlike her father's unwanted stowaway. As of #43 however, Vernage has been transferred to Ryuga to keep Evolto's DNA in check.
  • Tsundere: A platonic example to Sento and Ryuga, but especially towards Kazumi. She makes it very clear to him that she does not reciprocate his affections, even being disapproving towards his "monologue sessions", and often refers to him as "Grease" instead of "Kazumiin", even keeping that rigid stance up until he dissolved. Overall, regardless of how much she calls them out of their recklessness or how snarky she can be to them, she still cares about them very much.
    • Also best demonstrated in NEW WORLD: Grease, where she starts out with getting angry at Kazumi for thinking that what they were doing was a "date" when in reality she wanted to buy a birthday gift for Soichi, causing Kazumi to sail away on the boat with the Crows. However, upon her awareness of Kazumi's determination to save her and help stop Downfall, at the end, she ultimately reciprocates his feelings and agrees to date him for real this time, to his joy.
  • Unwitting Instigator of Doom: In #5, Ryuga asks her what happens to Smash when their essence is not removed after battle and she tells him that they probably return to Faust's base. This allows Ryuga to create a plan where he knocks Sento out and turns someone (Tetsuya, to be precise) back into a Smash.
    • On a larger scale, her entire situation as seen from #1 was orchestrated by Soichi to get her to produce more Fullbottles, under the impression that she was doing good.
    • It's because of her running towards the possessed Soichi that he ended up obtaining the means to become the Big Bad. Ironic considering how Vernage was trying to stop him.
  • Verbal Tic: Tends to append "-shi" to her words whenever she's fed up, usually after coming out of the purification chamber.

    Sawa Takigawa 

Sawa Takigawa

Portrayed by: Yukari Taki

A freelance reporter working in Touto, she seeks to uncover the mysteries behind the Smash and their foe, Kamen Rider Build. She's soon revealed to be much more than just a reporter, however: she's a spy for Namba Heavy Industries, the core financial backer of Faust. After her cover is blown by Misora, she's turned into the Stretch Smash and pulls a Heel–Face Turn afterwards, joining Sento's gang in order to fight the Namba Industries... or so we led to believe. In fact, she's one of the Namba Children, and always struggling to leave the organization after socializing with Sento and co.
  • Action Girl: While she can't stand against the superhuman Smash and other antagonists, Sawa's perfectly capable of handling escaping danger on her own without needing to be saved. At times she's even the one to save Sento and Banjo.
  • Beneath Suspicion: Neither the main characters nor Faust manage to figure out her identity until Misora finds her bug in the lab.
  • Brainy Brunette: #26 shows she understands schematics and is able to solder delicate circuitry. Sento even comments on this when she helps him work on his latest invention - Full Full RabbitTank Bottle and Fullbottle Buster.
  • Becoming the Mask: This is the crux of her actual Heel–Face Turn. Turns out when you give someone a family, and genuine affection that they didn't get as a child, they grow attached to both. Guess Juzaburo Namba isn't as smart as he thought.
  • Big Damn Heroes: While not the one that did the actual saving, Sawa is directly responsible for Nabeshima's family being safe and sound.
  • Bitch in Sheep's Clothing: At first, she was a Child Soldier spy who infiltrates nascita until her status is revealed, she was turned into a Smash by Faust and Namba, before she finally pulls a Heel–Face Turn... or so it seems, but she's actually on the run from Namba ever since.
  • Blatant Lies: When Sento questions the veracity of her Dark and Troubled Past, pointing out that there was no "Takigawa" amongst the victims of the bomb, she claims she took her mother's name after her father's death. Sento clearly doesn't buy it for a second.
  • Car Fu: Most of the show's vehicle-related stunts involve Sawa driving a car or truck, which proves effective both at dealing with Guardians and getting Sento and Banjo out of trouble with Hokuto's forces.
  • Defusing The Tykebomb: Courtesy of Sento, Ryuga and Misora as her Family of Choice.
  • Disappeared Dad: Her father died because of the government covering up Faust stealing the side panels of Pandora Box. It is actually just a cover story.
  • Good Counterpart: To Utsumi. Both were indoctrinated by Namba at a very young age, and both seemingly keep working for him, even after being forced into situations that would likely result in them getting killed off normally (Sawa becoming the Octopus Smash, Utsumi having to become Night Rogue to get Gentoku off the hook), and both eventually leave Namba's employment. However, Sawa pulls a full-fledged Heel–Face Turn, for reasons explained below, and is still quite sane. Utsumi, on the other hand, went from working for the Big Bad Wannabe to the real Big Bad...and at best, will likely end up in a mental institute.
  • Heel–Face Turn: After being turned into a Smash, she decides to tell Sento and the others everything. It stuck too. While Sawa was still feeding Namba some information, she was still aiding Sento along the way. Showcased beautifully in #27-28.
  • Hidden Depths: Initially hides her full capabilities until she's outed as a spy.
  • Intrepid Reporter: Tries to uncover the mystery around Smash and Kamen Rider. Her first reaction after seeing a Smash is to try and take a picture of it. Unfortunately, this put her life at risk in the process. This takes a darker turn once you learn that she's one of the Namba Children.
  • Nice Girl: Always polite and caring to her friends. She remains so even after her Heel–Face Turn when she finally considers her friends as family.
  • Redemption Earns Life: If she didn't she would have been just another statistic in Evolto's massive body count like the rest of the Namba faction.
  • Power of Friendship: The whole reason why she is still alive even later into the story. She was supposed to kill herself once found out like the Namba children are taught, but the time spent in nascita made her yearn for family and life.
  • Secret-Keeper: Due to Sento's and Soichi's mistakes, she becomes this after blackmailing them for info. Things turn out to be a great deal more complicated.
  • Social Media Before Reason: Deliberately invokes this with the Needle Smash in #1 to prompt Sento to save her, giving her an excuse to infiltrate nascita.
  • Tyke Bomb: She was raised as a Child Soldier of Namba Heavy Industries. It explains a lot about her numerous skills detailed above.
  • You Do NOT Want To Know: Her answer every time the other main characters ask how she got her intel.
  • You Have Outlived Your Usefulness: Faust turns her into a Smash after her cover is blown. Once she recovers, she switches sides. At least that's what it's supposed to look like... and it is!



    Vernage (SPOILERS) 


Voiced by: Sora Amamiya

The Queen of Mars who resides inside Misora's bracelet.

  • Action Girl: Is incredibly powerful and not afraid to use it.
  • Arch-Enemy: Is Evolto's. While she can't currently fight him on even footing, she's the reason he spent millions of years Sealed Evil in a Can and he's the reason she lost her entire planet and people.
  • Authority Equals Asskicking: The Queen of Mars and a Physical God.
  • Big Good: Saves the heroes multiple times, gives them the means to control the Hazard Trigger's powers, and warns them of Evolto and actively opposes him at every turn. In fact, she's the reason the heroes managed to have a fighting chance against him at all: she drained the bottles inside Pandora's Box so Evolto couldn't just open it and destroy Earth.
  • Brainwashed and Crazy: Vernage is consumed by her regret and anger at the loss of her home planet as the CD Lost Smash.
  • Cast from Lifespan: Using her powers burns up the time she has left before having to pass on, as such she's very careful to only use it when necessary.
  • Commuting on a Bus: She practically disappears during the back half of the show, only re-appearing when she became the CD Lost Smash and then once more at the end. This is mostly because Sora Amamiya came down with a case of Chorditis Vocalis from overworking her voice midway through the series, requiring her role to be reduced to keep the story moving. Justified In-Universe by the fact she can't even emerge without burning up what little time she has left.
  • Drama-Preserving Handicap: At full power she was capable of fighting a fully empowered Evolto to a Mutual Kill, so if she were at full power the series would likely have been very short. All her powers are Cast from Lifespan in her current state and thus have to be reserved for circumstances that only she can help with, and she can only emerge for very brief moments at a time.
  • Go Out with a Smile: Once she senses that Sento's defeated Evolto for good, she possesses Misora one last time to remark on it and then releases the bracelet's clasp and passes on with a smile on her face.
  • Last of Her Kind: Is the last Martian. Even though she's technically dead, this was true even before then.
  • Living on Borrowed Time: She's long dead and her Soul Jar can't sustain her for long, meaning each time she emerges she's losing time. As such she only intervenes when necessary. The dose of Nebula Gas that leads to her becoming the CD Lost Smash replenishes her power, though it's unclear to what degree.
  • Physical God: Her first display of power terrifies Seito enough that they fall back for the time being out of sheer fear of her. At full power she was capable of taking on full power Evolto one on one and fighting him to a draw.
  • Pyrrhic Victory: Vernage eventually managed to defeat a fully powered Evolto, but by the time she managed to do so, he had already wiped out the rest of the Martians and destroyed what was left of their civilization. Downplayed, however, as it still trapped him on Mars for millions of years and likely saved a lot of planets from being destroyed by him in the process.
    • Evolto and Shinobu tried to invoke this by turning her host, Misora, into the CD Lost Smash, as due to Vernage's power not even Genius Form could save her host from death. Sento bypassed this by using Genius Form's abilities to kick Misora into Ryuga and transfer Vernage to him so she'd survive.
  • Spanner in the Works: She's ultimately the biggest roadblock to Evolto's plans. If she didn't defeat Evolto all those years ago, he would have just continued his planet destroying spree. And if she didn't follow him to Earth and drain out the Fullbottle essences from the Pandora Box, Evolto would have won the second he touched the Box instead of just the Skywalls forming (not to mention that it means the heroes still have Fullbottles to fight back with after Evolto uses them to create the Evol Trigger).
  • Symbiotic Possession: Unlike Evolto, she's genuinely benevolent and heroic and Misora is very willing to have her around. She's saved everyone on multiple occasions.
  • Royals Who Actually Do Something: The Queen of Mars as well as the series Big Good.
  • Worf Had the Flu: The only reason she's unable to finish off Evolto herself is that her Soul Jar isn't able to sustain her indefinitely and her powers are gradually weakening. At her full power, she was able to fight a fully powered Evolto to a Mutual Kill and total the Evol Driver, leaving him stranded on Mars for millions of years.


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