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Tear Jerker / Kamen Rider Build

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"Even if he wanted to, he handed all the bottles over to the government. Besides... He can't like that."


     Episode 1: These Guys Are a Best Match 
  • Ryuuga saying that he may be stupid and basically trash, but he would never kill anyone. And meaning it. It's heartbreaking to see the poor guy look like he's on the verge of breaking down over the fact that no one believes him.
  • The backstory of the Skywall. Imagine how many families, relationships, and friendships were broken apart when the impassable walls split an entire country into three sections. Imagine how many people tried to scale a Skywall to be reunited with their loved ones only to be met with a barrier that kills on contact.
    • Even worse, we later find out that the people present when the Pandora Box was activated had their personalities inverted, with even good, kind-hearted people becoming violent, belligerent, and warlike. Imagine what it must have been like for their families and loved ones to suddenly have someone they cared about literally become a completely different person overnight, potentially ending those relationships. It's no wonder that Tajimi was struck with severe My God, What Have I Done? late in the series when Sento manages to restore her to her original personality.

     Episode 2: The Innocent Runaway 
  • Burn Smash, this episode's MOTW, is Ryuuga's girlfriend. Unlike other Smash, her body is so weak that defeating will outright kill her instead of separating the Smash essence from her body. Despite this, rather than harming Ryuuga, she turns her on flames on herself, until Sento Mercy Kills her, allowing Ryuuga and Kasumi only a brief moment to reconnect before she dies.
    Kasumi: If you'd never met me, you'd have had a much happier life. I'm sorry.
    Ryuuga: Don't be stupid! As if there could be a life better than this! For me... meeting you... gave me the greatest happiness.
  • Ryuuga's Despair Event Horizon and his following exchange with Sento.
    Sento: Let's go.
    Ryuuga: It's fine. It's doesn't matter anymore.
    Sento: What is? What's fine about this? Nothing about this is fine! (shakes Ryuuga) If you get caught now, you'll go back to being a murderer! And that's fine?! (shakes Ryuuga again and pushes him away) You think that's what she would want?!

     Episode 4: The Testimony Will Be Zero 
  • Nabeshima turns out to be alive after the events of #3, but being turned into Smash twice made him forget everything. He doesn't recognize Ryuuga and what's worse, he doesn't recognize his family either including his daughter.
    • His daughter promises to teach him how to do the cat's cradle and help him get his memory back
    • Ryuuga sobs when he realizes that Nabeshima genuinely doesn't remember him as it ensures his life will remain in ruins.
  • Knowing that Nabeshima saw a similar panel in Faust's lab and that Pandora's Box is missing two of its side panels, Sento digs the bottle matcher out of the wall to make sure. His suspicion proves to be right and he confronts Souichi, heartbroken that his adoptive family lied to him.

     Episode 5: Dangerous Identity 
  • Think about Tatsuya for a moment there. He gets to meet his BFF again after a year only to find a completely different person without any memory of him. Sato Taro is there talking to him and yet is effectively dead.

     Episode 6: Moonsault of Anger 
  • According to Souichi, Sento is as lost as Ryuuga and his nice persona (that Ryuuga just called God-like and Buddha-like) is how he copes with his Identity Crisis. He doesn't know who he is, so he tries to set a new identity for himself by being the good guy.

     Episode 8: What The Memories Tell You 
  • Katsurugi's father worked as a supervisor of Pandora Box and was Driven to Suicide by the pressure put on him from all sides blaming him for the Sky Wall incident.
  • Ryuuga complains that Mrs. Katsurugi's fried egg rolls, Her dead son's favorite, are too sweet. Sento tastes them and tells Ryuuga off for not liking them. Then his eyes water and he starts crying while eating them for reasons he can't explain due to his lost memories.
  • Mrs. Katsurugi cries after reading the note her son left her, reassured that he loved her.

     Episode 9: Project Build Trap 
  • Kuwata killing himself in front of Sento is sick and horrifying, but not exactly sad. The sad part comes in when you realize that Sento will probably blame himself for his death.

     Episode 11: Burn, Dragon! 
  • Kasumi wrote Ryuuga a letter, starting with saying that she will probably be dead by the time he gets to read it and that he should get over her.

     Episode 12: The Theory Of Conspiracy 
  • Sawa's father was murdered by Touto Government to cover the loss of Pandora Box' panels. Considering that they were stolen by Faust and Gentoku is Night Rogue, you can connect the dots who gave the order.
  • Utsumi's death is damn sad despite him not actually dying. He seems to have remorse over his actions for Faust and tries to warn Sento, but is shot before he says much.

     Episode 13: Who Takes Off The Veil 
  • Seeing everything crash around Sento. Soichi is Blood Stalk, who framed Ryuuga and manipulated pretty much everything and everyone into his plans. The realization only really starts setting in in #14, but he is still very distraught just by the possibility and it only becomes worse upon confirming it.
    • The episode spent so much time focusing on Soichi's desire to keep nascita open so Sento would have a place to come home to after his battles were over. Near the end of the episode when Sento and Ryuga return with Pandora's Box and nobody is there, Sento's saying "I'm back" to the empty room is sad enough, but becomes even worse just minutes later when you realize it's confirmed his suspicion that Soichi is Stalk, and leaves you wondering if all those warm words earlier were just another lie.

     Episode 14: The False Kamen Rider 
  • The preview alone starts with a low blow, with Souichi saying that Sento “was just playing the role of a hero”.
  • There’s something tragic about the TV debut of RabbitTank Sparkling and the fact it’s first opponent will be Souichi.
  • Sento's having flashback about his time with Souichi during his fight with the Blood Stalk. It hurts so much he slowly stops fighting or even defending himself.
  • Sento cries as the realization sets in. All he remembers in his life was manipulated or an outright lie.
  • Imagine what Misora would feel when she finds out truth. Her father was basically using her the whole time, a member of Faust and had caused the death of many innocent people. She would not be happy for sure. Sento and Ryuuga had decided not to confront her about the full truth about what happened with Souichi but it is doubtful that they will be able to conceal the truth forever.
    • The pictures on Toei's site imply that this is going to happen just about next week.

     Episode 15: Judging Sento Kiryu 
  • Misora finds out that her father is evil. She puts on a cheerful facade to delude him into thinking she did not. She breaks down a moment after he leaves.
    • What makes it worse is Souichi tries to throw her off the trail with a joke about growing coffee beans. The flashbacks to he and Misora laughing together while working at nascita imply that he might have genuinely started to care for her.
  • Taizan Himuro was probably aware that there is something seriously wrong with his son, but didn't know (didn't want to know/believe) just how much until now.
  • Preview of #16 shows Ryuga and Sento fighting because of the revelaton of #15. It seems that after finding out that Takumi Ktasuragi is not dead, Ryuga wants to make sure it will not stick. Or, according to the dialogue, that Sento has undergone a Heroic BSoD and Ryuga might be trying to snap him out of it.

     Episode 16: Weaponry Hero 
  • Sento is called out on his Dissonant Serenity and his response (lashing out at Ryuga) shows that it's the only thing that holds him together.
  • Sento is in turmoil over the revelation that the whole mess is his invention and he just wages on to complete the Sclash driver, pretty much dead on his feet any otherwise. Ryuga decides to beat out his frustration by challenging him to fight and is granted his wish even though Sento has little will to fight. And that is all when Sento is horrified of having hurt people before and not being able to remember all the things he should be sorry for.
  • Ryuga is angry at Sento for creating the inventions that killed Kasumi, but he is also angry at himself for not being able to stop being angry at Sento. He knows that Sento feels terrible and it's pointless blaming him for anything for as long as he has only vague knowledge what he should be sorry for, but being himself he just can't keep his emotions down.
  • A meta example. This episode aired very close to Christmasnote , but beside a mention and small celebration in the recap there wasn't even a mention of the holiday in episode itself. This shows that the events that befall to the cast makes them unable to even celebrate a holiday that normally brings people love and peace. Even worse is that Gentoku made a declaration of war in this episode which will bring lots of pain and grief through the entire series.

     Episode 17: The Outbreak of Rider Wars 
  • The whole episode qualifies as the war between Hokuto and Touto starts.
    • A highlight point will be Sento and Misora's scene. Misora blamed herself and tried to take her bracelet's off to no avail. Sento hugged her and takes responsibility instead of running away.

     Episode 18: The Golden Warrior 
  • Sento's desire to use Sclash driver on his own to keep everyone safe only results in him getting hurt and Ryuga being mad at him for trying to take a selfdestructive path, which he intends to take himself so Sento wouldn't have to.
    • Ryuga pulling a Taiga speech by claiming nobody's gonna miss him if he dies, thus he is the one who should use the Sclash driver. Like with Taiga, there is someone who calls him out on considering himself disposable.
    • He tries to soften the blow by jokingly telling Sento that he is the hero now (calling back to Sento's insistence on being the star of the story earlier in the episode) and couples it with a boisterous smile. Despite his best efforts, it still comes out sad. They both know what kind of hero Ryuga is.

     Episode 19: The Forbidden Item 
  • Sawa brings in information on Kazumi and Three Crows, revealing that he supported their families when the agriculture in Hokuto went down the tubes and when they didn't have anything to eat anymore, he signed up for military to be made into a weapon so the government would take care of them. They followed him and still remain loyal to him because of this.
  • Ryuga talks to Misora about how he doesn't want to watch Sento suffer so he uses the Sclash driver to fight for early end of the war.
    Ryuga: He doesn't smile anymore, you know?

     Episode 20: The Devil's Trigger 
  • Akaba talks about the Trio discarding their names when they became weapons and tries to convince Kazumi that he never calls them the nicknames they adopted because he remembers their real names. Kazumi just rebutts him and walks out.
  • Sento's dead set determination to save everyone, starting with Ryuga, even it means losing his most treasured belongings - his mind and identity to the power of Hazard Trigger. On the flipside, Ryuga wants to end the war as soon as possible even if it means becoming He Who Fights Monsters, leading to him getting into Gentoku's invasion plan.

     Episode 21: The Unstoppable Hazard 
  • Be warned. You're not going to leave this episode with a smile.
  • Kazumi rushes onto the scene, sees that Sento is going for the kill and transforms into Grease to stop him. He's too late.
  • Ryuga trying to stop a Hazard Trigger-affected Sento from continuing to attack the rest of the Hokuto Three Crows after Aoba goes down, knowing that Sento actually doesn't want to hurt or kill people, only to be harshly backhanded out of the way.
    • Forced out his transformation, Sento is confused for a moment before looking at Kazumi holding a dying Aoba in his Smash form. He starts to realize what happened and looks at Ryuga with the most anguished expression he's ever had as if looking for confirmation that what he's suspecting is wrong. When Ryuga doesn't say anything, Sento looks back at Kazumi and asks the question.
    Sento: (barely holding back tears) Did I do it?
    • Akaba and Kiba charge at Sento in blind fury to kill him barehanded and Kazumi stops them, because even thought he is hurt as they are, he doesn't want them to take their anger out on Sento when he is down.
  • Sento being rendered a depressed nigh Empty Shell by the trauma of losing control and killing another human being.
    • Taizan Himuro comes to Nascita to find out why Build has not shown up on the battlefield for week, only to find Sento in this sorry state.
  • When Sento goes to Aoba's grave to pay respects, he has a full blown panic attack complete with a hallucination of Aoba and even begs Kazumi to hit him as retribution for killing his ally.
  • Ryuga's reaction to Aoba's death. He blames himself for causing it as he was the one who went to take on Hokuto and forced Sento to use the Hazard Trigger to save him. The memory of Sento's terrified face after his transformation dropped caused him to lose all motivation to fight the remaining Crows and Grease. Made worse when he tries apologize to them for Aoba's death and gets brutally kicked by Kazumi for doing so.
    • Kazumi's reasoning makes it worse, He believes that if Ryuga isn't ready to kill then he shouldn't be on the battlefield. Everything about his interactions with the main heroes is tailor made to highlight that War Is Hell.
  • Soichi tortures Sento by casually talking about all his worries and thoughts that hurt him. He makes it so Sento feels every word, causing him to snap and charge at Soichi in blind fury just to shut him up.
  • The Next Episode preview raises some worrying possibilities. For one, Sento seems to have been forced into using the Hazard Trigger again. For another the episode itself is called "Tearful Victory" and we're treated to Misora practically screeching the following line in what seems to be horror with the visual of HawkGatling Hazard standing stock still.
    Misora: Don't! Sento!

     Episode 22: Tearful Victory 
  • Sento tells Misora that using the Anti-Hazard Trigger device is not murder. He is just a weapon. Misora proceeds to rip Sento a new one for saying that, yelling at him that he is human, a stupid human who always puts people's happiness before his own well-being. Sento's heartbroken expression reveals his earlier calm proclamation as lie that he's trying to convince himself to believe just to be able to keep on going.
  • Ryuga being obviously distraught by watching the match on TV as he couldn't be on the sidelines for various reasons.
  • Misora sobbing her heart out in Sawa's embrace in the end of the representative match and after it. The feelings seem to be mutual among all participants, it just depends on how good they are at holding them back. And then just when things finally seem like they'll calm down Seito declares war on Touto.
  • Kazumi clutches his and Aoba's dog tags while being reminded that they are always together by Akaba and Kiba.
  • The preview features Kazumi clutching bleeding Kiba in his arms before the next cut shows him attacking Engine Bros and howling in pain in a gravel field. Seems like Grease might lose another comrade.

     Episode 23: Western Phantom 
  • Kiba is taken hostage by the Washio Brothers and Mido asks Kazumi to become a weapon in service of Seito or Kiba and the workers on his farm die.
    • As predicted from the preview, Kiba dies in this episode, taking a blast intended for Kazumi.
      • Even worse, Kiba hints that the beating he got from the Kaisers did a number on him and probably would have died either way.
  • Ryuga is angry over being unable to help Kazumi and Akaba save Kiba because Seito's attack would only intensify if he and Sento went into Hokuto. Even after everything that happened and with control over the Sclash Driver he still can't end the war. His anger over the futility of everything is very much justified.

     Episode 25: The Idol Awakens 
  • Akaba and Kazumi agree to burying Aoba and Kiba's dogtags on the Sky Road since that's all they have left. What's worse, Poor Masaru doesn't even get there as he dies shortly after.
  • As if Kazumi's sorrow in losing more men is not enough now he's lost Masaru. One wonders if he'll truly recover after the war ends or even survive the whole ordeal given the hell he's endured.
    Kazumi: Why the hell didn't you run dumbass...?! I guess that's you to the letter. Dumbest guy I knew. But you cared about your friends more than anyone. And in the end you lost because of it...! But y'know, Masaru...That's exactly why I was proud of you the most.

     Episode 26: Treacherous Deathmatch 
  • Just Sento's reaction that he almost strangled Misora (his closest friend) when he went berserk.
  • Kazumi makes a grave for all his lost friends like he agreed with Akaba. It's just a shame he has to add Masaru's dogtags along with Syuuya and Syoukichi's
  • In the end, everything heartwarming about Sawa's relationship with the main cast was for nothing since it turns out she's a Nanba Child. Everything, from the very beginning to her seeming Heel–Face Turn was fake.
    • She is essentially Child Soldier version of Soichi. She pretended to be an ally, wasn't around for extended periods of time, was outed once before the full reveal and so on...

     Episode 27: Hero's Counterattack 
  • Sento hesitates upon being asked whether he doesn't believe that he and Gentoku are weapons. On some level, he still believes that crap Soichi told him earlier.
  • Sento says that science doesn't create tools for war, but Gentoku calls him out on creating the Hazard Trigger even though he knew it could hurt a lot of people. He doesn't have answer to this for a while.

     Episode 28: The Genius Comes On A Tank 
  • During Sawa confessing to Sento that she's a Nanba Child, she also explains that during her time with the heroes she felt actual familial warmth for the first time. This lead to a conflict of interest with her orders from Nanba to kill herself before she could be captured and caused her to realize two things. One: Nanba doesn't give a damn about her no matter how loyal she is, and Two: she's become the mask. All of this makes it even more heartwarming when Sento still accepts and cares about her.

     Episode 29: The Opening Bell Rings 
  • Seito, now under Nanba's control, declares further war effors against Touto and even puts the blames on Touto for this.
    • This means Kazumi still can't go home. He is justifiedly heartbroken, because he fights with all his strength all the time and it's still not enough.
  • As Ryuga tears into Sento for letting Kazumi leave to go back to Hokuto, Misora sadly points out that neither she nor Sento has any right to stop him because the war is their fault (Sento for creating Faust and Misora for purifying the FullBottles).

     Episode 30: The Truth of Pandora's Box 
  • The Reveal that Souichi has been possessed the whole time, with the dialogue indicating he's been aware but unable to control his own body—meaning that he's had to watch as the thing possessing him not only commits atrocities against others, but also psychologically traumatises and deceives his own daughter.
    • That's not even getting into how hard Souichi must have been mentally screaming in terror as whatever is possessing him tried to murder Misora at the start of the episode.
  • Sawa and Misora are worried about Sento going off on his own. Kazumi even slaps Sento for making Misora cry after catching up to him.

     Episode 31: Surging Magma! 
  • Ryuga's anger and increased Hazard Level waver when Gentoku hits him with a cruel reveal. Stalk knew Kasumi didn't have a high enough Hazard Level to survive exposure to Nebula Gas and did so anyway so her death would cause Ryuga's Hazard Level to grow higher due to anger. Whatever Stalk's, or rather Evolt's plan is required Ryuga suffering the death of the woman he loved.
    • On that topic, Ryuga still feels pain over Kasumi's death 29 episodes after the fact. Most series in recent memory would've had him work past losing her by about the midway point and then never mention her again.
  • Ryuga gets knocked out of transformation and Sento jumps in to protect him. Saying this distressed Ryuga would be a major understatement. His sobbing speech about how much has Sento done for him while he can't even protect him back as he is trying to get up definitely brings the point in.
    • All of this happens while Stalk is beating Sento to death in front of Ryuga (again to play with his emotions) and Kazumi is unconscious on the ground not very far away.

     Episode 32: Programmed Tragedy 
  • Utsumi blackmails Kazumi by demanding Pandora Box and Touto bottles in exchange for the workers on Kazumi's farm. And since he is left to guard Pandora Box, the temptation is there. He despairs over not being able to save them as doing so would ruin everything.
  • Ryuga is very distraught over being told that he is not human. He tries to find some other explanation for why he could operate Pandora Box without completely panicking, but failes in face of evidence.
  • Ryuga sits by Kasumi's grave, talking about the ditch he is in now.

     Episode 33: Final Weapon: Evol 
  • This episode gives us a Harsher in Hindsight look to Gentoku's actions since becoming Rogue. Stalk explained that Gentoku hasn't been influenced by the Pandora's box AT ALL since he became a Rider, and he's been playing the bad guy to unite the nation and give it to his dad, because he thinks that Taizan is the only one capable of leading the nation properly. It also means that now, free from the Box's influence, he can look back on the horrible actions he committed with Faust and he can truly feel guilt about them.
  • Out of options and desperate, Gentoku pleads Sento to help him. Crosses into heartwarming since he needed help to save his father.
  • Misora got hit real hard this episode. She found out that her own father hasn't been in control of himself for ten years and she was talking to a genocidal alien maniac wearing his face. Then when Rogue knocks Stalk out of his transformation, Misora can only see her father in pain, and tries to help him, only for Utsumi to take advantage and give Evolt the tool he needed, and then she had to watch her father's hands be used to murder Taizan in front of her eyes.
  • Taizan Himuro sacrifices himself to protect Gentoku from Evol. To say that Gentoku is heartbroken would be major understatement. He is dazed from shock at first, but then he dives in to hold him close. He realized that his father really loves him just a little too late.

    Episode 34: Severing the Best Match 
  • The title couldn't be more fitting as the "Best Match" in question is of the one established back in the beginning. Sento and Ryuga. After his final clash with Evolt, Ryuga winds up getting possessed by the genocidal alien after one hell of a Hope Spot. The way Kazumi starts shaking his head like he doesn't want to believe what he's seeing is true when Ryuga starts talking with Evolt's voice is heartbreaking.
    • What's worse, we don't see Souichi after the final clash, leaving his fate ambiguous. Is he finally free of Evolt after a decade of horrifying servitude, or did Souichi actually die in that clash? Thankfully the next episode reveals that he's alive but catatonic.
    • And it's all punctuated by Evolt transforming into Dragon Form, reducing the proud and Badass Cross-Z to nothing more than a form change for himself. That evil laugh the Evol Driver makes at the end feels like Evolt laughing cruelly at the heroes as they watch their friend become their greatest enemy.
  • Misora grabbing Evolt and angrily/sobbingly screaming for it to give her her father back.

    Episode 35: Tower of Destruction 
  • Evolt spends all of Sento's desperate and hopeless attempt to defend the Pandora's Box explaining everything about how Ryuga and he are two halves of the same whole, thoroughly pummeling Sento in the process. Once Sento's beaten and can't even stand anymore however, Evolt decides to torment Sento more by explaining about how he threatened Shinobu Katsuragi, Sento's dad, into repairing the Evol Driver and how the guilt he felt for aiding the genocidal alien was very likely the real reason Shinobu was Driven to Suicide. Evolt explains this so casually and flippantly, there's no way he wasn't explaining it for the sole purpose of hurting Sento.
    • And then, during his fight with Sento later, he imitates Ryuga's voice in order to fake a Fighting from the Inside moment to get Sento's guard down only to shout "Gotcha!" and cruelly attack him to retrieve the remaining Fullbottles and open the Pandora's Box.
    • Evolt copying Ryuga's voice is also a cruel Hope Spot for the viewer. Thought that maybe The Power of Friendship would force Evolt out and allow the heroes to stop the Pandora Tower from forming because we've still got many episodes to go until the finale? Wrong.

     Episode 36: The Star Hunting Evolt 
  • Kazumi defeats Gentoku in a fight and tells him to think about what he felt when his father died so he can relate to the deaths he had caused himself.
  • Misora trying to yell some sense into Sento when he is about to leave for his final battle with Evolt, extending to when Sento plans to use the Pandora panel to unleash a suicide attack against Evolt. She doesn't want to lose anyone else.
  • Ryuga's horrified reaction when he wakes up, only to find out that Evolt has possessed Sento.

     Episode 37: The Ultimate Phase 
  • Ryuga can't transform because Evolt has taken all of his essence when he left his body. He tries to fight and desperation has him tackle Evolt and take the Dragon EvolBottle from his belt. He then proceeds to try and punch Evolt out of Sento with predictable results.
    • It gets better. He manages to fix that, but then the combined attacks of Cross-Z Magma, Grease and Rogue unlocks the Evol Trigger. This, in turn makes Evolt leave Sento, which is good only until he wakes up and proclaims himself to be Takumi Katsuragi. Ryuga's Oh, Crap! is very justified.
  • Ryuga's attempt to convince Gentoku to help him fight against Evolt and rescue Sento. Gentoku tries to dissuade him from trying by reminding him that he's responsible for Kasumi's death but Ryuga breaks down and admits that he just doesn't want to lose the people he has left. Unfortunately Gentoku responds that he can't help because the Rider System responds to the user's emotions, which would make him less useful as he's still in the throes of a Heroic BSoD following his father's death.

     Episode 38: Mad World 
  • The nascita gang coming to terms with the fact that Katsuragi took Sento's place. They have absolutely no idea what to do now besides to just keep on fighting.
    • There's also the implication that Katsuragi would be back permanently, meaning the Sento they all knew would gone forever.
  • Katsuragi talks about the original intention behind the Rider System - fighting Evolt. He is heartbroken upon finding out that Gentoku used it to start a war between the regions and tears him a new one for doing so. Still, he admits he played a part in it, too.
    Takumi Katsuragi: I sold my soul to the Devil.
  • Rai's Cruel and Unusual Death. Disintegrated by a black hole from Evol's attack opening up beneath him. His last actions are to hurl his Engine Gear to Fu and tell him that it was all up to him now before perishing into the void with extreme pain. What's worse is that when Fu transforms into Hell Bros he forgoes his Nebula Steam Gun, and therefore the bulk of his most powerful attacks, out of absolute rage. The melancholy track that plays during this clues the viewer in to the fact that Fu's not going to make it either.
  • Fu taking the blow of a Black Hole Finish from Evol in order to protect Ryuga. The blow is fatal and Fu dies in Ryuga's arms.
    • What's worse is Ryuga's reaction to him dying. He desperately tries to grasp at the fading motes left behind before punching the ground in anger.
    • From a meta perspective, the death of the characters becomes worse with the knowledge of their suit actor passing away as well.
  • Katsuragi justifying Misora's time in Faust as being 'in the name of scientific progress' and his visible and audible pain at the death of the Washio brothers shows that he's more affected by his own actions than he shows. It makes sense when you consider Sento using Dissonant Serenity as a coping mechanism.
  • Katsuragi sounds so small when he's lamenting that another life has been lost, crying at the deaths of Rai and Fu. Coupled with the revelations that he constructed the Rider System to defeat Evolt and fulfill his father's last wish, it seems like people dying as a result of that goal is something of a Trauma Button for him. One has to wonder if he had a similar reaction every time a Smash subject died.

     Episode 39: Unstoppable Genius 
  • Misora asked Takumi if he really did shows no trust in his comrade. Remembering how he lamented both Gentoku and himself for the start of the war, Takumi responses that it only hurts if he did so. Judging from his words, its implied that Katsuragi does want to have friends but his betrayal and how the Rider Systems being abused completely shatters his faith in others. A demon he may be, but deep down, that was another point of Katsuragi's soft spot aside from his family.
  • Just as Takumi try to exit nascita and help the other Riders, an injured Gentoku pleaded Katsuragi to trust him, and from his looks, he is genuinely driven guilt for manipulating and/or taking advantage of Katsuragi and Utsumi.
  • Katsuragi Takumi remembers being Sento and, realizing just how his quest to destroy Evolt negatively impacted his own personality, relents his place as the main personality of their body to him. The next episode lessens the impact somewhat by revealing that Sento can still contact Takumi.

     Episode 40: Revolution of the End 
  • Ryuga gets mad at Kazumi for trying to do something stupid, because he cares about the guy and knows he might not last to see the end of this.
  • Kazumi runs off on his own and infiltrates Faust in Hokuto, which leads to him being experimented on. Now his Hazard Level is high enough to use Dragon Jelly, but also to disappear when he is defeated. It's also implied that if Kazumi loses himself to the effects of Nebula Gas, he counts on Sento stopping him with any means.

     Episode 41: The Truth of the Best Matches 
  • The reason for the Best Matches is revealed. When Evolt possessed Soichi, he probed his memories for thirty things that he liked. Soichi replied with thirty things that he remembered that Misora liked and those became the Organic Fullbottles. Then, Evolt probed for things that could destroy those things. At first he got straight answers such as tanks and gatling guns, but then Soichi started giving nonsensical answers such as erasers and comics because he wanted to protect the things that his daughter loved. This serves as a cruel reminder that Soichi was just a normal man who was exploited by an evil being who wanted to destroy everything he cared about.

     Episode 42: Legacy Of Doubt 
  • Evolt declares himself the country's leader and is accepted by happy crowds. This makes Gentoku question if he can fulfill his father's wish and Utsumi takes the oppurtunity to demoralize him as much as possible. This nearly ends with Gentoku dead as he can't fight unless he gathers all the shaky faith he has.
  • Sento tells Katsuragi that their father created the Rider System for good ends. Katsuragi is too jaded to believe him.
    • Sento's absolutely heartbroken face when he sees his dad helping Mad Rogue just multiplies the first point.

     Episode 43: Another Build 
  • Sento has Heroic BSoD through most of #43 because of seeing his father again and as a villain.
    • Even when Ryuga, Kazumi and Gentoku jump into fight with another Build, Sento just stands still and sobs quietly.
  • Kazumi rips into Sento for defending Shinobu Katsuragi. Sento keeps on looking away from him and when shaken, idly mutters a defense.
    Dad is not our enemy.
    • He keeps a blank face through the whole scene, but the way he bites nails and messes with hair after Kazumi leaves shows the anxiety simmering inside.
    • Kazumi is mad at Sento, but also wants him to acknowledge the truth because that might hurt less than holding on a false truth. Seeing no response, he claims not to trust Sento anymore and goes off on his own. Gentoku tells Sento that he is too wrapped up in believing his father and follows Kazumi. Blindly following his ideas was pretty much Gentoku's Fatal Flaw as Night Rogue and helped Evolt steer him right where he needed him.
  • Unable to find anything that would help him from the ditch he is in, Sento smacks the computer monitor off the table in a burst of anger. Misora tries to comfort him by reminding that he is their hope, but he tells her it's no use and there is no point in believing anymore.

     Episode 44: Evolt's End 
  • Evolt tells Sento that either he gets CD Lost Bottle or he will murder everyone Sento cares about without breaking a sweat. This makes Sento throw his phone against the pavement in anguish and go out to fight Evolt while everyone else is asleep to keep them out of danger. Ryuga, Kazumi and Gentoku are hurt/angered by what they perceive as Sento's lack of trust in them.
  • Perhaps this episodes crowning moment of Tear Jerker, Sento's father pulled a Xanatos Gambit on him. He showed the weakness of the Triggers, both Hazard and Evol, so the Kamen Riders would defeat Evolt and purify the Lost Bottles. But if Evolt won, then they would still get the test subjects needed for the remaining Lost Smash. Either way, Evolt won. Thankfully, the next episode confirmed that Shinobu had pulled a fast one on Evolt and was only thwarted by Evolt having contingencies in place.

     Episode 45: Hope's Scientist 
  • Shinobu manages to pass some crucial information to Sento before he dies. His final act is to lovingly ruffle Sento's hair as he used to do with Takumi.
    Shinobu: Takumi, you've gotten taller again.
    Sento: (in shock, grasping at the air his father have dissolved into) No, I haven't.
  • Misora comes out of the lab and is asked how is Sento. She says he has been working on the computer all night and everyone immediatelly knows it's bad.
  • Katsuragi refuses to acknowledge that there may have been still something good to his father, because his trust has been hurt so many times he doesn't want to care anymore. He refuses to face Sento through the whole exchange, implying that despite his words he does mourn him after all.

     Episode 46: An Oath to Be the One 
  • Sento gives Kazumi the Blizzard Knuckle and warns him to only use it as a weapon because if he uses it to transform, he will die. Kazumi says it doesn't matter, only for Sento to assure him that everyone would miss him. Everyone looks devasted in #47's preview. Go figure.
  • Evolt split off a part of himself to create fake Hokuto Trio specifically to stab Kazumi in the back and twist the knife full cirle. Kazumi fights them, but can't hurt them. Beaten down, he recounts how their deaths permanently damaged him and apologizes for breaking his promise to Sento. He is not coming back from this battle.
  • A moment from the end of the episode as Kazumi transforms using the Blizzard Knuckle knowing full-well that it could and probably will kill him.
    Build Driver: Are you Ready?

     Episode 47: Frozen Flame 
  • Misora tells Kazumi why she never called him by his name. She was afraid doing so would wind up causing him to hit a Death Flag and was afraid she'd lose him. Unfortunately, she's admitting this as Kazumi is dying. The last thing he sees is her hugging him close and begging him to not die. He's crying during the exchange too and tells her he regrets knowing that he's leaving the nascita crew behind.
    • Misora finally calls him "Kazumin"... After he's died.
  • Utsumi puts his all into fighting Evolt, is fatally wounded by overusing the Evol Driver and then killed by Evolt when he shields Gentoku and Sawa with his body.
  • Ryuga realizes that Grease is a different color when stopping to watch the transmission of his fight for moment. Then the realization hits him. He makes a grab for Sento and yells at him for giving Kazumi such an item as dangerous as the Blizzard Knuckle and even inventing it in the first place. Sento doesn't answer and just gives Ryuga a look saying "I did what I had to." Ryuga gets it and just kind of folds into himself before letting go. Then Sento says that have to go and they continue to the tower's top.
  • The gang has made it to the tower's top and started recovering before the final round, looking like a battered and bruised pile of human misery.
    • Misora reunites with them and you can't hear her telling the rest that Kazumi's died due to the audio for the scene cutting out for drama. This doesn't make seeing their reactions any easier. Sento just stands there in horror, Ryuga punches a wall in futile anger. Sawa hugs Misora, her hands still bloody from when she was tending to Gentoku's wounds, and Gentoku, who'd formed a sort of friendly rivalry with Kazumi, screams in anger and sorrow.
  • Sento's scream at the end where Evolt waltzes in like nobody business is all his guilt, sorrow and anger condensed into one word. He looks ready to strangle him barehanded if given a chance.
    Sento: EVOLT!!!

     Episode 48: To The World of Love & Peace 
  • If Kazumi's death wasn't enough, the previews show that Gentoku is the next one on the chopping block. He ends up dying, attempting to immobilize Evolt by damaging his Evol Trigger. It ends up successful after his death.
  • In the last minutes of the episode, Ryuga knocks aside Sento and forces him out of his transformation as Sento was going to sacrifice himself to destroy Evolt, only to do it himself and tell his friend "Thanks" before flying himself and Evolt into the distortion to complete the fusion of the two Earths.
    • His reason? He's got Evolt's DNA in him, and if Evolt's going to go, he has to as well.
    Ryuga: I got Evolt's DNA in me. It makes sense for me to go down with him.

     Final Episode: The World Build Created 
  • "My friends built Kiryu Sento... They created Kamen Rider Build!"
  • Takumi Katsuragi dies for real this time, acknowledging that Sento was correct.
  • Sento's plan succeeds, but there's no a place for him in the new world. Because "Sento Kiryu" was created by the old world, nobody remembers him (Misora has a brief moment of "Have we met before?" but that's it) and there isn't a place for him, either as Takumi Katsuragi or Taro Sato (he exists as his own person, and Soichi mistakes him for Sato). He's essentially become a nomad, though this is mitigated when he finds out that Banjou is there too.
    • However, it's actually worse for Banjou: There's already a Ryuga Banjou in this world, one who's a successful MMA fighter and whose girlfriend Kasumi is alive and well. And original!Banjou is fully aware of this, meaning he gets to see what his life could have been but will never be.

Movies and specials

    Heisei Generations Final 
  • Sento tells Parado that it must be nice to have a place he belongs to.
  • Ryuga falls into the crevice created by the colliding worlds and Emu catches him. Ryuga tells him to let go as he would rather die than drag Emu down with him.
  • Ankh's return was something any OOO fan would be crying tears of joy over. Sadly, he only lasts to the end of the movie before his conscious Core Medal breaks again. He was just enjoying an ice pop in front of Eiji as he faded away and the Medal, now split in two again, fell to the ground. Mitigated somewhat by the fact that Movie War Mega Max confirms that Eiji manages to fully revive Ankh in the future and that this is most likely the first step.

    Kamen Rider Build: Birth! Kuma Televi!! VS Kamen Rider Grease! 
  • Kazumi is furious that Massugu let himself be experimented on, just so he could return the favor to Kazumi. It's the same with the Hokuto Three Crows too and he feels horrible for endangering them all. Thankfully, Massugu went home and survived, turning up again when Nanba had the workers on Kazumi's farm rounded up to be killed by Gentoku.

    Kamen Rider Build: Be the One 
  • Thanks to the Blood Tribe's brainwashing, all of Japan hates Sento. Literally all of Japan. Even Misora and Sawa.
  • Ryuga betrays Sento to the villain of the movie thanks to being brainwashed.

    New World: Cross-Z 
  • Yui and her students. They saw Cross-Z, who ignored them and ran off to fight more Guardians. Then they were taken by Faust and turned into Lost Smash, then tortured until they died and perfected the Lost Bottles for Evolt. And Yui remembers this. And her students are left in a coma from the Nebula Gas still in their systems.
  • Evolt casually revealing that Banjou's parents were killed by him to escalate Banjou's Hazard Level. Banjou is visibly shaking before he cleans Evolt's clock. Evolt has long since passed the Moral Event Horizon, but he appears to have a knack for finding shovels to keep digging himself deeper.
  • When Evolt discusses how Kilbus destroyed Planet Blood, he sounds oddly sorrowful, indicating that he had fond memories of his homeworld, or perhaps the people on it. Whatever the case, it's obvious that Kilbus is a major part of what drove Evolt to become the Planet Eater he is in the show. This also indicates that without Kilbus, it's possible Evolt may have had noble qualities, and that the loss of his home and loved ones sent Evolt over the Despair Event Horizon and straight into the looney bin.

Example of: