Series / Kamen Rider Build

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Well then, shall we begin the experiment?note 
The Formula of Victory has been decided!

The 2017-2018 entry in the Kamen Rider series; the nineteenth entry in the franchise's Heisei era, and the twenty-eighth entry overall.

Ten years ago, Japan launched Project Prominence: the first successful expedition to Mars. If that wasn't enough, the astronauts managed to bring back with them proof of extraterrestrial life on the red planet - a strange cube with strange properties, found in ancient ruins. This artifact holds the potential of discovering a source of unlimited clean energy. With this incredible asset in their hand, all signs pointed at the advent of a Golden Age for Japan. But then everything went wrong.

During the celebration of the expedition, where the cube was for the first time shown to the world, a mysterious man barged in and, after a struggle with security, reached out and touched the object. This resulted in its activation and caused the sudden appearance of the Skywall - a giant, crimson-glowing wall that violently tore through Japan, and even reached miles into the sea. Not only that, everyone present at the event were warped by the energies of the cube, increasing their inherent aggression. This resulted in the nation being divided into three opposing states - Touto, Seito, and Hokuto.note . Each one with a separate government and doctrines, but all desiring the massive power of the artifact - which after the Skywall disaster became known as "the Pandora's Box" - for themselves.

In the present day, Touto holds custody over the Box, but a new crisis shakes the region - the appearance of humans-turned-monsters known only as "Smash". While the government evades the topic, there is a hero hunting down the beasts. Unbeknownst to all, his identity is a young genius physicist named Sento Kiryu, a young amnesiac who was taken in by a cafe owner when he was found in a rainy alley with no memories of anything except his escape from experimentation on by an evil organization called Faust. Now, as he searches for clues about his past, he uses the Build Driver to transform into Kamen Rider Build and personally combat Faust and the Smash, his powers augmented by "Fullbottles", bottles containing essence of Smash purified by the cafe owner's mysterious daughter.

It premiered on September 3rd, after Kamen Rider Ex-Aid finished its run; and it airs alongside Uchu Sentai Kyuranger, and later, Kaitou Sentai Lupinranger VS Keisatsu Sentai Patranger, on the Super Hero Time block.

Kamen Rider Build's tie-in projects include:
  • Kamen Rider Heisei Generations FINAL: Build & Ex-Aid with Legend Riders, the annual crossover movie; here featuring Kamen Rider Ex-Aid as Build's co-star.
  • Kamen Rider Build: Birth! KumaTelevi! Vs Kamen Rider Grease!, a Televi-kun magazine exclusive DVD special.
  • Kamen Rider Build: Raising the Hazard Level ~7 Best Matches~, a web series.
  • Kamen Rider Build: ROGUE, a mini series featuring Night Rogue exclusive to the DVD collections.

There exists a character sheet and a recap page for the series. Please place any related tropes there.

Recurring Kamen Rider tropes include:

  • Cool Bike: Build has the Machine Builder, a motorcycle that transforms from a smartphone with the Lion Bottle.
  • Early-Bird Cameo: Build first made appearances in Kamen Rider Ex-Aid: True Ending and in Ex-Aid episode 44; in the latter he tried to get a sample of Ex-Aid's power but mistook Genm for him instead, leading to a fight.
    • The Kaiser-type enemy first appeared in Heisei Generations FINAL.
  • Finishing Move: Build has "Vortex" moves; "Vortex Finish" moves in Best Match forms, "Vortex Break" when using weapons, and "Vortex Attack" while in mismatched Trial forms.
  • Henshin Hero: If you're expecting something else at this point, you might as well give up.
  • Home Base: Sento and Ryuuga's hideout is located beneath cafe "nascita", which doubles as Sento's lab. The entrance is hidden behind a fake refrigerator.
  • Humans Are the Real Monsters: It's clear from the start that the Smash are just innocent victims of horrific experimentation; the real evil are those doing the experimenting.
  • Merchandise-Driven: Another Toku show, another set of toys to sell. This series' focus is on the Fullbottles.
  • Monster of the Week: Smash, monsters born from human experimentation by Faust. Like Gaim and Ex-Aid, though, the main threat is from evil Riders, with the kaijin being more treated like Elite Mooks.
  • Multiform Balance: Build follows the Kamen Rider OOO model here, with specific combinations ("Best Match"es) being stronger and given more focus.
  • Phlebotinum Rebel: Played with several ways:
    • To start with; Sento, Misora, and Ryuga have all escaped from Faust and are using stolen Faust tech to fight their captors.
    • Subverted when it turns out Faust is letting them do this, since as far as they're concerned the Riders are doing their R&D for them. More than that, unknown to the heroes, they're being directly supervised by a Faust agent. They discover this and kick him out, playing the trope straighter afterward.
    • And then it's revealed that, before his amnesia, Sento was one of Faust's founders and its main researcher - he's rebelling against himself.
  • Sixth Ranger: The secondary rider is Kamen Rider Cross-Z (pronounced just "Cross", or maybe like "Crozz" - either way, it's not "Cross-Zee").
  • Transformation Trinket: The Fullbottles are the source of power, which characters use various devices to access. Shaking Bottles by themselves can confer a weakened version of their powers to whoever does so (ex. Sento shakes Rabbit a bit to get a burst of speed).
    • Kamen Rider Build uses two Bottles at once in the Build Driver, one with an organic power and one with inorganic. The Bottles tend to be grouped by their region of origin:
      • The Touto combos are Rabbit/Tank, Gorilla/Diamond, Taka (Hawk)/Gatling, Ninjya/Comic, Panda/Rocket, Harinezumi (Hedgehog)/Shoubousha (Fire Truck), Lion/Soujiki (Vacuum Cleaner), Dragon/Lock (and Key),note  Kaizoku (Pirate)/Densha (Train), and Octopus/Light (as in Light Bulb).
      • Hokuto gets Phoenix/Robot,note  Wolf/Smapho (Smartphone), Kuma (Bear)/Televi (Television),note  Rose/Helicopter, Turtle/Watch, Unicorn/Keshigomu (Eraser), Scorpion/Gold,note  Spider/Reizouko (Refrigerator), Kabutomushi (Beetle)/Camera, and Dog/Mic.
      • Seito has Tora (Tiger)/UFO, Kujira (Whale)/Jet, Kirin (Giraffe)/Senpuuki (Electric Fan) and Same (Shark)/Bike debut in Raising the Hazard Level; Shika (Deer)/Pyramid, Penguin/Skateboard, Obake (Ghost)/Magnet, Hachi (Bee)/Sensuikan (Submarine), Sai (Rhino)/Dryer, and one more.note 
      • For upgrades, Sento tends to enhance his RabbitTank combo. The first is RabbitTank Sparkling; where the others are water bottles, this one's a soda can with a "carbonated" version of the form. He can also use an add-on called the Hazard Trigger to upgrade any Best Matchnote  into a "Super Best Match", activating a "Hazard" version. Later on, Build can use the Full Full RabbitTank Bottle in conjunction with the Hazard Trigger to access RabbitRabbit Form or TankTank Form.
      • A Santa/Cake combo was also released as promotional items for Christmas.
      • And, of course, there are Legend Rider Bottles for previous Riders. These involve the same organic/inorganic pattern as Build's other Bottles - Double and Ex-Aid get wholly unique combos with Meitantei (Detective)/USB Memory and Doctor/Game, respectively; while others have a single Bottle that pairs with one of Build's usual ones: OOO's Bottle is Medal,note  Fourze's is Yuujou (Friendship),note  Wizard's is Mahoutsukai (Magician),note  Gaim's is Orange,note  Drive's is Keisatsu (Policeman),note  Ghost's is Parka,note  Decade's is Card,note  and Den-O's is Momotaros.note  While Trial Forms work as normal, Legend Best Matches turn Build into a duplicate of the original Rider.
      • A second set of Legend Rider Bottles represent the Riders themselves, with two subsequent Riders being Best Matches for each other: Fourze/Wizard, Gaim/Drive, and Ghost/Ex-Aid. Ex-Aid also gets two versions of his bottle, for his Level 1 and Level 2 forms.
    • Kamen Rider Cross-Z uses the Dragon Fullbottle with the Build Driver and an add-on called the Cross-Z Dragon.
    • Members of Faust use Transteam Guns to transform, with Night Rogue using a Bat Bottle and Blood Stalk using a Cobra Bottle.
    • A second belt, the Sclash Driver, is used by Kamen Riders Grease, Cross-Z, and Rogue. While the Sclash Driver can use Fullbottles to activate finishers, Grease and Cross-Z instead use gel packets called Sclashjellies; Grease uses the Robot Sclashjelly while Cross-Z uses the Dragon Sclashjelly to access an upgraded form, Cross-Z Charge. Rogue doesn't use a Sclashjelly, but a special Fullbottle called the Crocodile Crack Fullbottle.
    • The Kaisers use Nebula Steam Guns with "Gear" Fullbottles; one uses the Gear Engine and the other uses the Gear Remocon (Remote Control).
    • The Three Crows of Hokuto each have a Bottle that they use to become Hard Smashes: Castle, Kuwagata (Stag Beetle), and Fukurou (Owl).
  • Weapon of Choice:
    • Just as Build has several forms, he gets several weapons to go with those forms:
      • The DrillCrusher, which switches between drill (or rather, drill-shaped sword) and gun forms. This is his default weapon and is not tied to any specific form. Sento and Ryuuga also use them in their human forms.
      • Gatling forms get, of course, a gatling gun called the HawkGatlinger.
      • Ninjya and Comic forms use a Cool Sword called the 4-Koma Ninpoutou; which activates ninja techniques of duplication, fire, wind, and smoke bombs.
      • For Kaizoku forms, he has the KaizokuHassyar bow.
      • RabbitRabbit and TankTank have the Fullbottle Buster; another sword/gun combo but much bigger.
    • Cross-Z has his own Cool Sword, a music-themed blade called the Beat Closer.
    • Grease and Cross-Z Charge both use a wrist blaster/pilebunker hybrid weapon called the Twin Breaker.
    • Night Rogue and Blood Stalk each have a Transteam Gun and Steam Blade, which can combine to form a rifle.
    • The Kaisers use updated Transteam Guns called Nebula Steam Guns, which can also be combined with the blade. Kamen Rider Rogue also has a Nebula Steam Gun.

Kamen Rider Build provides examples of:

  • After the End: The End being a Type 1 Regional Apocalypse caused to Japan (skirting Type 2 in Hokuto).
  • Alternate Universe: Build is the first series to not use the Shared Universe concept established by Decade at the turn of the millennium, presumably because nobody would buy a Hand Wave like "Japan's been split in three since 2007, we just never brought it up before now". Confirmed by Heisei Generations FINAL, which has this series take place in "the World of Build", suggesting a Decade-style parallel universe.
  • Apocalypse How: The Sky Wall Disaster was a Regional Type 1. Japan's society as they know it has been more or less completely destroyed, resulting in a more dystopian situation in all three capitols. Hokuto is skirting a Type 2 as the Skywalls altered the soil, causing a famine and economic collapse.
  • Applied Phlebotinum: Nebula Gas, supposedly emanating from parts of the Skywall's own foundations, and thanks to Takumi Katsuragi's research, able to mutate people into Smash.
  • Arc Words: As the show goes on, the Build Driver's intense "ARE YOU READY?" slowly turns from a silly toy jingle to a confirmation of Sento's will to keep going even as everything goes wrong. First seen after he finally gets over the reveal that he is actually Katsuragi the Devil Scientist, then when he decides to keep fighting as Build for the sake of his friends even through his PTSD-level terror of the Hazard Trigger's effects. When it's used like that, the voice clip usually gets the time to echo into the distance instead of going straight to the rest of the transformation.
  • Artifact of Attraction: While Pandora's Box being a potentially super powerful energy source is one reason everyone wants it, the way Gentoku talks about it implies it's more than that and it's in some way actively compelling those infected by its Hate Plague to desire to claim it as their own and use it to Take Over the World.
  • Artifact of Doom: Pandora's Box, which was discovered on Mars and taken back to Earth. When opened, it released the Skywall and increased the aggression of everyone present at the event. This led to the divide of Japan into three separate states. Faust has one of its panels that shed off when it opened and the heroes have the other one, both of which are involved in creating the Bottles involved in Smash and Build's powers. It also altered Hokuto's soil in such a way that their crops withered and died, causing a famine. The Nebula Gas used to create Smash monsters in the first place also actively emits from the Sky Walls, meaning every single bad thing in the show can be traced back to the Pandora's Box in some form.
  • The Bad Guys Are Cops: Because both Ryuga and Sento are on the run, they must often fight against Touto's Guardian forces while dealing with Smashes. At least before the war with Hokuto begins. Now they're must fight together with Gentoku/Night Rogue to protect Touto.
  • Balkanize Me: Due to the appearance of the Skywall and the adverse mental effect it had on the politicians at the event, Japan got split both literally and metaphorically into three different states, each with their separate governments and doctrines. Reality Ensues, as the balkanization of Japan has made it extremely weak on an international level, and the threat of foreign invasion or domination is brought up as a pressing concern. The new nations are:
    • Touto (Eastern Capital), set around eastern Honshu. They adhere to traditional pacifism and is the main setting of the show.
    • Hokuto (Northern Capital), consisting of Hokkaido and northern Honshu. While allegedly focused on social welfare, most of their efforts have instead gone into developing their military power at the expense of their citizenry.
    • Seito (Western Capital), with a territory made of Shikoku, Kyushu and Western Honshu. They pursue economic recovery in face of the incident.
  • Beware the Superman: Night Rogue and Blood Stalk have comparable power to Build and are Rider-like in nature. The show makes zero attempts to hide how absolutely terrifying the concept of an unfettered, psychopath with with punches and kicks in the double digit tons of force would be to go up against if you're a normal human. On several occasions, normal human soldiers are pitted against them and are easily slaughtered. The best example of this would be in episode 11 when Blood Stalk back hands a human guard in the face and obliterates him, then effortlessly dissolves a second with his venom, doing so with almost casual ease. To make matters worse, Night Rogue's ultimate plan is to mass produce Kamen Riders as Super Soldiers...
  • Big Bad Ensemble: Five separate villainous factions emerge, each with their own agendas:
  • Book Ends:
    • With the abdication of Emperor Akihito on April 19, 2019, Build is almost just in time to be a Meta example, providing one for the entire Second-Phase Heisei era, being a Rider with a Half and Half design similar to Kamen Rider W who solves mysteries (Shotaro) and collects data while trying to remedy his amnesia (Phillip). There will be one more Rider series in the Heisei Era after Build, but with luck it will be like Decade and further the Book End.
    • Likewise, the series' plot is the result of an expedition unearthing something evil while exploring the ruins of a long-extinct, previously unknown civilization, just like the first Heisei Rider series, Kamen Rider Kuuga.
    • An internal version: In Episode 14, Soichi calls Sento to the alley where they met in the first place and Soichi "found" the amnesiac Sento one year prior. The battle goes into a nearby warehouse but ends right back in the alley, where Sento declares "The man I knew as Soichi Isurugi is dead."
  • Brains and Brawn: Genius physicist Sento and former pro-fighter Ryuuga.
  • ...But He Sounds Handsome: Sento exhibits this when he serves as the narrator, recapping the events of last week's episode. He calls himself a "hottie and brilliant physicist" and deliberately plays up his more virtuous characteristics, as well as exaggerating Ryuga's more negative aspects.
  • Civil War: The first act of the series is the long, slow buildup to one: the peace between the three capitols is paper thin, and with the exception of Touto, the prime ministers are just looking for an excuse to break it. It's ultimately Night Rogue and Nanba's goal to set off the powder keg and start a Japanese civil war for their own ends. By the end of the first act, they succeed, and the second act deals with the war itself in all its horrors.
  • Combo Platter Powers: Build uses the same style of powers as Kamen Rider Double, where two different items are used at once and the resulting form has aspects of both. In this case, all forms are a mix of something organic and something inorganic.
  • Continuity Nod: As seen in Heisei Generations FINAL:
    • Gentaro is already a teacher, in accordance with Movie War Ultimatum which shows the Kamen Rider Club 5 years in the future. While in reality it's been a bit longer than that, it's been stated that Heisei Generations FINAL occurs one day before Movie War Ultimatum.
    • Likewise, Kouta is already a space god in this movie, and he's currently on "vacation" at the World of Build.
  • Darker and Edgier: Most Kamen Rider series for the past few years had been fairly lighthearted, with a few (like Gaim and Ex-Aid) taking a turn for the worse later. This one starts out with unethical human experimentation, an innocent man being framed for murder and goes from there. Only Amazons trumps Build in terms of Downer Beginning, and that one was specifically geared towards adults.
  • Department of Redundancy Department: Riders since Kamen Rider Gaim have had Legend Rider form changes, which give them costumes based on previous Riders, but in the current Rider's aesthetic. Rather than have unique costumes, Build's Legend Rider Best Matches cause him to turn into the past Rider outright while retaining his own belt. This includes being able to turn into Decade, whose gimmick was that he could turn into any past Rider while retaining his own belt.
  • Does This Remind You of Anything?: A country suddenly and forcibly divided by different policies (an additional side effect to actually being physically divided) leading to antagonism amongst itself as well as outside forces... it's really a Toku take on the North Korea situation.
  • Dug Too Deep: Pandora's Box was unearthed by an expedition to Mars and brought to Earth, resulting in it releasing the Skywall.
  • Fantasy Helmet Enforcement: Helmets being pulled out of nowhere is justified, as the first episode shows that the Machine Builder has an app that can make a helmet materialize for anyone riding to wear.
  • Five-Man Band: Nascita/Team Build develops into one before episode 13, where they become a Four-Man Band:
    • The Leader (and The Hero): Sento Kiryu acts as the de facto leader of Team Build and the protagonist of the show. He plans most of the groupís activities and acts as their primary combatant in the field as Build, while the other characters provide support through their various talents. Emotionally he acts as the core of the group, providing a strong moral center and source of advice to the less experienced Banjou, while the others keep Sento's eccentric side in check.
    • The Lancer: The position initially belongs to Souichi Isurugi before passing to Ryuga Banjou after Souichi's departure. Souichi acts as an older parental figure to everyone, especially Sento and Misora, providing Sento with his counsel and being the one who first encouraged him to become Build, while Banjou matures into the role after tempering his early selfishness.
    • The Big Guy: Ryuga Banjou/Kamen Rider Cross-Z becomes the muscle of the group, as the only one outside of Sento that can fight as a Kamen Rider, with his hotheaded and impulsive attitude clashing with Sento's cool and collected nature. Each also pushes back against the other's self-loathing tendencies, providing each other with emotional support in times of crisis.
    • The Smart Guy: Sawa Takigawa acts as the master of espionage and information gathering, particularly once she drops her early reporter guise and becomes willing to use her full abilities and connections with Nanba Heavy Industries to fight back against them. She's also enough of an Action Girl to save both Sento and Ryuga when all hope is otherwise lost, or at least help them escape.
    • The Chick: Misora Isurugi begins as a cold Deadpan Snarker in contrast to Sento and her father's antics, but over time she warms up to the rest of nascita and becomes supportive and positive in her own way, playing the role of sister to Sento and providing Banjou with an abundance of Ship Tease. She also provides them with support through her status as the idol Mii-tan, whose legion of devoted fans provide her with considerable versatility when it comes to gathering information on Smash attacks, raising funds, or seeking out obscure services.
  • Gone Horribly Wrong: Project Prominence was meant to bring hope for the future of mankind, but after the Pandora's Box created the Skywall, it only managed to fracture Japan.
  • Gotta Catch 'Em All: When all 60 of the Fullbottles, paired as their Best Matches, are inserted to the various panels of the Pandora Box, something "crazy" is supposed to happen.
  • Hate Plague: The opening of Pandora's Box released some kind of energy that permanently raised the aggression levels of the country's leaders present at the event living, making cooperation in the face of the Skywall dividing the nation impossible.
  • Hero with Bad Publicity: Being labeled a fugitive does Build no favors. In episode 3, a couple of bystanders assume that Build is attacking some Smash targets instead of defending them.
  • Idiosyncratic Episode Naming: Or more like numbering. So far all the episode numbers were shown with an equation first then their solution as the episode's number. Doubles as Freeze-Frame Bonus.
  • Kick the Dog: Faust does this as early as episode 2. After Ryuga escapes them, siccing a Smash on him could be considered a reasonable response. But they go the extra mile and turn his fiancée into that Smash, seemingly with the full knowledge that she couldn't handle the process and therefore would force him and/or Build to either leave her a monster or Mercy Kill her.
  • Laser-Guided Amnesia: One debilitating side effect of Nebula Gas exposure is short-term memory loss, which Faust often uses to cover their tracks. They rely on it a bit too much, however, which becomes a liability when one subject's amnesia proves to be temporary.
  • Lensman Arms Race: Like its predecessor series, Build moves at a lightning pace with its upgrades, but does so in a much more horrifying context. Blood Stalk manipulate characters on all sides to take more and more dangerous risks with their minds and bodies for an advantage over their opponents that's ever more fleeting, all while seemingly unconcerned with his own place on the power scale. Then one looks at the planet where the Pandora Box used to reside, and sees it's a lifeless wasteland.
  • Linear Warriors, Quadratic Wizards: The Transteam Gun users start with much higher Hazard Levels and stronger abilities than the Build Driver users, but the Transteam Gun forces the user to stay locked at that fixed level, which makes it useless in the long term except to deliberately serve as a Starter Villain.
  • Meaningful Name: Nanba Heavy Industries, Faust's financial backer. The "nan" in Nanba can mean "south", the one compass direction left out of the three regions, and Nanba is implied to be a Mega Corp. powerful enough to be its own faction.
  • Mecha-Mooks: All of the factions, including Faust, make use of the Guardian humanoid robots to supplement or replace their human troops. This is because they're manufactured by Nanba Heavy Industries, which had war profiteering as one of their prime motivations for helping start a Civil War in the first place and thus will gladly provide them to all sides.
  • Mood Whiplash: The story sure has some abrupt transitions between silly and horrifying. Face doodling and memories of being experimented on in span of five minutes, folks.
  • Mugged for Disguise: Ryuga gets to pull this off in episode 10, greatly expanding his options.
  • Mundane Solution: Apparently motorboats are all that's needed to find and slip through gaps in the Skywall (you need a special pass to travel legally, though), and wireless signals can go right through if the three state leaders can still teleconference every month. Underground tunnels also weren't affected, and weapons of sufficient force can just blow a hole in the thing. It's eventually made explicit that the physical barriers formed by the Skywall aren't actually what's keeping the country divided, but rather the insanity and lust for power that the Pandora Box inflicted on Japan's leaders, and the Skywall is just there to be an excuse to stay divided and act as a source of Nebula Gas.
  • Nebulous Evil Organisation: Faust, the organization that are responsible for the Smash. Night Rogue and Blood Stalk are Faust's high-ranked members. They're actually an unsanctioned military project run by a leading member of Touto's government, and nearly every named character at the Touto Institute of Advanced Matter Physics is actually a member of Faust.
  • Once-Green Mars: Implied; the Pandora's Box was found in ruins on Mars implying a civilization once thrived there.
  • Phlebotinum-Handling Requirements: Not everyone can use the Build Driver, one needs a Hazard Level of 3 or more. If anyone else tries to use it, they're painfully electrocuted, as Ryuga finds out the hard way.
  • Power Levels: "Hazard Level" is the measure of a subject's resistance to the effects of Nebula Gas, and accordingly how much of its power they can draw out. Level 1 is the minimum, and indicates a subject who will die if turned into a Smash and the essence is extracted. Level 2 is the typical level and refers to subjects who can survive essence extraction. Level 2.1 or higher allows the subject to maintain their human form rather than become a Smash, and Level 3 is the minimum to use the Build Driver. Increasing levels above 3 appear to improve the strength of the user's Rider form: for instance, a Level 3.2 Vortex Finish does nothing to harm Blood Stalk, while the same attack at Level 3.7 successfully injures him. Methods of increasing one's own Hazard Level include intense anger.
  • Pretext for War: It becomes apparent Touto is the only one of the three groups formed from the fractured Japan to actually want peace, and the other two are looking for any excuse to start an all out war. Justified, as Touto was the only faction whose leader isn't corrupted by Pandora's Box's Hate Plague. Night Rogue decides to give them a reason by stealing Pandora's Box from the institute where it's kept under lock and key and only accessible by all three leaders at once.
  • Previously On: Done by the characters, as if to contribute further to the Mood Whiplash.
  • Primary-Color Champion: Build's default RabbitTank form is half-red (from the Rabbit Fullbottle) and half-blue (the Tank), with a decent amount of black from the undersuit, admittedly.
  • Public Domain Artifact: A cube found during an Mars expedition was called the Pandora's Box after being opened it released the "Skywalls", kickstarting the series.
  • Psycho Serum: Nebula Gas. Exposure transforms you into a powerful monster...who's completely insane and a rampaging beast. Subverted with the purified liquid form inside the Full Bottles, which lacks this effect. Unfortunately, turning an essence from the liquid form into the solid jelly form turns it back into a Psycho Serum that increases the user's aggression with each use. The Hazard Trigger does the same thing to an even larger extent with the basic Full Bottles by overclocking them to insanely high levels.
  • Reality Ensues:
    • The entire country being split into three pieces in a cataclysmic event is treated as a gigantic disaster, and the fact one of the three countries is devoted to economic recovery shows it had more impact than just geological.
    • While travel between the countries is possible, travel between mainland Japan without going around the Skywalls isn't. There are small openings in the Skywalls, but they're few and far between and too small to be reliable means of trade or moving between the separate sections. This combined with the Hate Plague Pandora's Box unleashed ultimately lead to the three divided areas growing away from each other and unable to recover from the disaster until they've become separate countries.
    • The whole mess with the Skywalls has weakened Japan to the point other countries are trying to annex them.
    • Hokuto's soil was altered by the Skywalls and their crops were completely devastated. This caused an economic collapse and people are extremely desperate to escape to the other countries due to the resulting famine.
    • Criminal organizations don't just get money from nowhere. Faust gets its funding from the Nanba Industries, which also gives them a bit of blackmail material to use to manipulate the organization.
    • The Guardians are cannon fodder to the heroes, who even without their suits are superhuman, but they're still heavily armed robots much stronger than a baseline human. When pitted against normal human soldiers, it doesn't go well for the humans.
    • The Riders can deal with the Smash on their own, and pretty much mow down any lesser variety after a certain point. When put into a military context and pitted against normal humans, they're dangerous Super Soldiers.
  • Revisiting the Roots: According to Word of God, the series is intended to do this. The most obvious case is the return of some Showa Era conventions like the monsters being created through experimentation by an evil organization, but other older Rider formulas can be seen, such as the parallels to W, and there being only one Rider until later when a single secondary Rider appears with only one base form and no gimmicks.
  • Robot Buddy: Cross-Z Dragon, a robotic dragon that turns into Cross-Z's Build Driver add-on.
  • Science Hero: "Science" is the big theme the way the last few Riders were themed around video games, ghosts, and cars. His Rider Kick even summons and follows a line graph.
  • Sealed Evil in a Can: The series is kicked off by Pandora's Box being opened and releasing the Skywall and dividing Japan into three separate countries.It also released a Hate Plague on those in close proximity and the Skywalls emit Nebula Gas, which is used to turn people into the Smash monsters.
  • Set Bonus: Some of Build's Bottle combinations make the Build Driver declare "Best Match"; it's not clear what makes the Bottles so compatible, but the resulting form is more powerful than non-Match ones. Each Bottle has a label on the cap that helps indicate its Best Match combo (for instance, Rabbit and Tank have "R/T" labels). Playing around with the Build Driver toy revealed that it's pre-programmed with sounds for 32 Best Matches total, not counting promotional or Legend Rider items.
  • Spell My Name with an "S":
    • The toy catalog labels the Ninja Bottle as "Ninjya". Unlike most of Toei's odd Romanizations, is apparently a legitimate (if uncommon) way to spell the word in Japan.
    • One magazine scan got its Ls and Rs mixed up, labeling a suit "GolliraMond Form".
    • As per usual, official English spelling of characters' names tended to differ from what the fanbase guessed they were. Night Rogue was originally thought to be Knight Rogue or Nitrogue, among other things; while Blood Stalk was thought to be Blood Stark. Ryuuga's Rider name was first thought to be "Close" based on pronunciation, then most people adopted "Claws" as it matched his dragon theme. Even when evidence emerged that it was "Cross", nobody expected it to have Xtreme Kool Letterz and be "Cross-Z".
    • "KaizokuRessya" Form and its "Kaizoku Hassyar". More accurate romanizations would be KaizokuRessha and Kaizoku Hasher.
  • Super-Fun Happy Thing of Doom: Each of Japan's new regions is seemingly devoted to benign and benevolent ideals and social practices. All three are also effectively at war with one another for Pandora's box and keep tight grips on the citizenry under their respective controls.
  • There Are No Therapists: None of the government leaders have been investigated for their mental stability in the wake of the Skywall event. If anything, the whole thing about them being affected mentally is an open secret.
  • Tomato in the Mirror: Talking with Ryuuga about the similar experiments that were done on them makes Sento realize that their purpose was to create Smash monsters, the very foes he fights against.
  • Vitriolic Best Buds: Sento and Ryuuga in spades. The only scenes they share where they aren't bickering and making constant digs at each other are the dramatic ones. They even bicker in the Opening Narration!
  • The Wall Around the World: The Skywall, unleashed by Pandora's Box, split Japan into three parts. Downplayed example, since the barrier stretches only from the center of Japan and fades into the sea before reaching any other country.
  • War Arc: As of episode 16 one has started when all out war between Touto and Hokuto begins with the heroes caught right in the middle.
  • War for Fun and Profit: Night Rogue and Nanba both seek to start an all out war between the three groups, but for different reasons. In Night Rogue's case, it's so Touto can come out on top of what he sees as an inevitable war, and in Nanba's case, he's simply a good old fashion war profiteer seeking to make money off of the resulting weapons deals.
  • Was It All a Lie?: Asked verbatim in Episode 14 by Sento to Soichi. The latter responds "Not ALL of it", admitting that there were times when Sento and Ryuga legitimately surprised him and when he felt bad about betraying them. However, Sento dismisses this as a bad joke.
  • Was Once a Man: As part of this series' call backs to older Rider series' (especially classic Showa Era style Riders) the Monsters of the Week, the Smash, were normal humans who were experimented on and turned into monsters. However, they're turned back to normal instead of killed similar to the Dopants or Zodiarts unless some terminal illness or debilitating condition still affects the human, in which case they're Killed Off for Real, but it's not that bad.
  • Wham Episode: Much like the previous series, episode 10 kicks off a long chain of them as the entire premise of the show up to that point begins to unravel.
  • When It All Began: The Skywall disaster ten years ago, which divided Japan into three regions.
  • World-Wrecking Wave: Pandora's Box being opened unleashed a localized one for Japan. The Skywalls violently erupted from the ground across the country, causing property damage and throwing any poor person too close to them hundreds of feet into the air, a Hate Plague was unleashed on those in close proximity, Hokuto's portion of the country had its soil altered such that a famine resulted, and Nebula Gas is being constantly emitted by the Skywall, which can mutate people into horrible monsters.

http://tvtropes.org/pmwiki/pmwiki.php/Series/KamenRiderBuild