A "Caixa de Pandora" foi encontrada em Marte. Um incidente ocorre com ela, fazendo-a emitir uma energia. Uma imensa parede emerge do solo, "Skywall", dividindo o Japão em três países. Dez anos depois, em Touto, um desses países, monstros chamados de "Smash" atacam as pessoas, e Kamen Rider Build luta contra eles. Sua identidade é Kiryuu Sento, físico gênio, sem memórias de seu passado.
Episódios
1. Eles são a Combinação Perfeita
3 de set. de 2017 25m 7.5Sento Kiryu starts his new job at the Touto Institute of Advanced Matter Physics, researching the mysterious Pandora's Box. While responding to a potential Smash sighting, Sento comes across a wanted fugitive...
2. Fugitivos Inocentes
10 de set. de 2017 25m 9.0The Kamen Rider of Touto is now a fugitive, due to his part in saving a convicted murderer - Ryuga Banjo. Kiryu begins to see similarities in the mysterious experiments both he and Ryuga were subjected to.
3. Fronteira da Justiça
17 de set. de 2017 25m 7.0The investigation into Ryuga's kidnapping leads to a man named Nabeshima. But to get the answers he needs, Ryuga must cross the border to Seito...
4. Zerando as Provas
24 de set. de 2017 25m 9.0The mysteries of the past continue to pile up as Sento investigates the Pandora's Box disaster. In Seito, Ryuga and Sawa continues the search for Nabeshima's family.
5. Identidade Perigosa
1 de out. de 2017 25m 7.0Sento confronts Owner on his involvement with Faust. Sawa finds a lead on Sento's elusive past.
6. O Moonsault Furioso
8 de out. de 2017 25m 8.0Ryuga finds the entrance to Faust's hidden base. Aiming to learn more, Sento learns of the late Katsuragi's research into "Nebula Gas".
7. O Cientista do Demônio
15 de out. de 2017 25mSento and Ryuga need to learn more about Katsuragi and his research. Setting their sights on Hokuto, they first have to get through the Sky Wall...
8. A Memória Inicia a sua História
22 de out. de 2017 25m 8.0Now hidden in Hokuto, Sento and Ryuga try to learn more about Takumi Katsuragi from his mother, and find his hidden project data.
9. A Armadilha do Projeto Build
29 de out. de 2017 25m 9.0A debate about the nature of Katsuragi's research leads to another falling out between Sento and Ryuga. Under pressure from a backer, Faust hatches a plan to steal Pandora's Box.
10. A Tecnologia da Destruição
12 de nov. de 2017 25mAs the three Prime Ministers of Japan meet, Blood Stark leads an attack on the Touto Institute of Advanced Matter Physics.
11. O Dragão Fulgurante
19 de nov. de 2017 25m 9.0With the majority of his Full Bottles now in Night Rogue's possession, Sento reveals his trump card - a way for Ryuga to use the Build Driver.
12. Teoria da Conspiração
26 de nov. de 2017 25mSawa reveals a connection between Faust, Nanba Heavy Industries, and the Touto Government. Sento and Ryuga plan to recover Pandora's Box.
13. Quem Vai Tirar o Véu?
3 de dez. de 2017 25mA surprise call from Nabeshima lays the foundation for Sento's plan to reclaim Pandora's Box, and a chance to capture the elusive Blood Stark...
14. O Falso Kamen Rider
10 de dez. de 2017 25mBlood Stark's identity is revealed, and Sento races against time to finish a counter-measure against him.
15. Julguem o Kiryuu Sento!
17 de dez. de 2017 25mWith Pandora's Box safely in their possession, Sento and Ryuga go after Gentoku, set on revealing the link between Touto's government and Faust to the public.
16. O Herói É Uma Arma
24 de dez. de 2017 25mGentoku reveals the truth behind Sento's missing memories, and the reality may tear his and Ryuga's friendship apart.
17. Começa A Guerra dos Riders
7 de jan. de 2018 25mHokuto invades Touto, looking to claim Pandora's Box for themselves. As civilian casualty numbers raise, Gentoku's government instigates Kamen Rider as their military weapon.
18. O Soldado Dourado
14 de jan. de 2018 25mA new contender in the Rider Wars appears before Sento and Ryuga, somehow weilding his own Sclash Driver. Hokuto's own Rider, Grease, has arrived.
19. O Item Proibido
21 de jan. de 2018 25mAnother clash between the Touto and Hokuto Riders ends with Ryuga struggling from the Sclash Driver's effects. The Hokuto Crows are given a way to power up by Blood Stark, but there's a cost...
20. O Gatilho Demoníaco
28 de jan. de 2018 25mSoichi gives Sento the means the stop Ryuga's growing rage with the forbidden item - the Devil's Trigger. Gentoku plots a counter-attack against Hokuto's invaders.
21. Hazard É Imparável
4 de fev. de 2018 25mO uso do "item proibido", o Hazard Trigger, modificou Build em uma armadura preta: Hazard Form. Nas palavras de Katsuragi Takumi, que desenvolveu esse item, se o usuário continuar a lutar na Hazard Form, ele perderia totalmente a consciência. Dito e feito: o item usado para impedir Ryuuga se voltou contra Sento, pois ele perde consciência durante a batalha, mas depois de enfrentar o trio...
22. A Vitória Dolorosa
11 de fev. de 2018 25mTouto and Hokuto's governments have ordered a winner-takes-all battle to decide who keeps Pandora's Box. It's Build vs Grease to decide the victor of the Rider War!
23. Fantasma do Oeste
18 de fev. de 2018 25mSeito delivers an ultimatum to Kazumi - fight for them as their Kamen Rider or witness the death of his family. A mysterious new adversary makes his way to Touto to confront Sento and Ryuga.
24. Aquele que Chamam de Rogue
25 de fev. de 2018 25mKamen Rider Rogue has revealed himself; Misora collapses inside the base.
25. O Despertar da Idol
4 de mar. de 2018 25mMisora sends Kamen Rider Rogue flying through Skywall; Souichi reveals to Sento that there is a spy in the Touto government.
26. Duelo Mortal Traçoeiro
11 de mar. de 2018 25mSeito challenges Touto to a best-of-three battle to decide who keeps Pandora's Box; Sento works to find a counter to Black Hazard's berserk state.
27. O Herói Vai Contra-Atacar
18 de mar. de 2018 25mRyuuga is tricked into losing his match; Build and Rogue face off as Sawa arrives with the schematics stolen from Sento.
28. O Gênio Chega de Tanque
25 de mar. de 2018 25mKamen Rider Rogue receives the data on Build's Rabbit Rabbit form, forcing Sento to unleash Tank Tank form; Sawa's backstory is revealed while Kazumi rescues civilians; Nanba decides to not play fair, taking control of Seito and declaring war.
29. Os Sinos da Abertura Ressoam
1 de abr. de 2018 25mDespite their promises, Seito continues their assault against Touto. All this is made worse as Blood Stark completes a panel of Pandora's Box, and the Skywall begins to shift...
30. A Verdade da Caixa de Pandora
8 de abr. de 2018 25mBlood Stark wonders how the Queen of Mars is still alive. Mysteries begin to arise as she singles Ryuuga out to become hope.
31. Jorre com Tudo, Magma!
15 de abr. de 2018 25mSawa and Misora discuss what the story behind Ryuuga really is; Team Build raid Pandora's Tower in an attempt to reclaim Pandora's Box, but Blood Stark stays one step ahead, goading Ryuuga into action.
32. Tragédia Programada
22 de abr. de 2018 25mRyuuga learns of his alien origins; Nanba takes Kazumi's friends hostage in exchange for Pandora's Box.
33. Evol, a Arma Extrema
29 de abr. de 2018 25mSouichi holds the Touto Prime Minister hostage in exchange for Sento to give him the Evol Driver.
34. Separação da Combinação Perfeita
6 de mai. de 2018 25mSento is poisoned by Evolt, who then negotiates a deal with Ryuuga for the cure.
35. A Torre Destruidora
13 de mai. de 2018 25mEvolt is now in possession of Ryuuga's body and goes after Pandora's Box. Sento reaches out to Gentoku, who has the last of the bottles.
36. O Planeta Vira Presa do Evolto
20 de mai. de 2018 25mPandora's Tower is complete and Evolt stands ready to destroy Earth. Kazumi is still angry with Gentoku for killing his friend and challenges him to a fight; Sento works on a way to harness Pandora's Box into a power-up for Build.
37. A Fase Final
27 de mai. de 2018 25mIn order to keep Evolt from getting Pandora's Box, Bernage moves the entire cafe to a different location; Ryuuga can no longer transform and so he and Kazumi go to Gentoku for help in saving Sento.
38. Um Mundo Insano
3 de jun. de 2018 25mSento has now lost all his memories and reverted to Takumi Katsuragi; Evolt gives Utsumi and the rest of Nanba an ultimatum.
39. Gênio Imparável
10 de jun. de 2018 25mUtsumi has now taken on the role of Kamen Rider Mad Rogue; Takumi creates a new bottle to fight Evolt, but also plans to take out Ryuuga as well.
40. Revolução Final
17 de jun. de 2018 25mKazumi is bummed that Evolt has stolen the bottles of his lost friends. Sento travels to his mother's house in Hokuto for answers about his father, but he and Kazumi end up face to face with a new Smash.
41. A Verdade Das Combinações Perfeitas
24 de jun. de 2018 25mSento learns that his father actually is alive; Sawa goes to find the one Faust experiment that, to their knowledge, has no relation to the Kamen Riders; Misora discovers that the Best Matches are about her.
42. Um Legado Duvidoso
1 de jul. de 2018 25mSento suspects that since Evolt has the Lost Bottles, he also has his father; Evolt plans to reunite Japan while Gentoku mopes over his dead father.
43. O Outro Build
8 de jul. de 2018 25mSento's loyalties are questioned concerning his father; Misora makes a deal with Evolt.
44. O Fim de Evolto
15 de jul. de 2018 25mKazumi and Gentoku get caught in order to raise their hazard level; Sento builds Ryuuga a new power-up.
45. O Cientista da Esperança
22 de jul. de 2018 25mIt turns out that Evolt is still alive, but Sento's father is able to tell him about a secret white panel in Pandora's Box.
46. A Promessa de Ser o Escolhido
29 de jul. de 2018 25mEvolt reveals himself to the world; Sento plans to combine their world with a parallel world via the white panel; Kazumi asks for a new power up.
47. A Chama de Zero Graus
12 de ago. de 2018 25mKazumi uses his new weapon to battle the clones of his former friends; Gentoku does battle with another set of clones and gets help from an unlikely ally.
48. Por um Mundo de Amor e Paz
19 de ago. de 2018 25mWith Kazumi now gone, it's time for the final confrontation with Evolt.
49. O Amanhã Construído pelo Build
26 de ago. de 2018 25mRyuuga has flown away with Evolt. Sento decides to go bring him back as the two worlds are about to merge.