Kamen Rider Build: Be The One

Kamen Rider Build: Be The One (劇場版 仮面ライダービルド: ビー・ザ・ワン) is the summer movie adaptation of Kamen Rider Build, double billed with the 's summer movie, '.

The film will be released on Blu-ray and DVD on January 9, 2019.

Synopsis
Set after the events of the Japanese Civil War, the newly appointed governors of Seito, Hokuto and Touto now support each other in their mission to reunify Japan, however they are secretly members of Evolto's home clan known as the Blood Tribe, who each have assumed government positions in order to take over the entire world. Being certain that Sento Kiryu/Kamen Rider Build is a major threat to their plans, they proceed with their Build Annihilation Plan (ビルド殲滅計画) to manipulate Sento's friends and other civilians against him. With Ryuga Banjo now against him, Sento must find a way to fight and survive as he hunts for the truth to stop the Blood Tribe in succeeding with their ultimate plan.

Plot
The movie begins with a POV shot of the Pandora Box being released and the walls going up, it appears to be from Sento’s eyes and his father telling him to get somewhere safe. Quick cuts to present day with a public conference of the unification of Seito, Hokuto and Touto and the designation of a governor for each region with Pandora Tower at its center. Sento is complaining about the heat while riding his bike on the phone to Sawa and Misora. He comes across a brother and sister being attacked by two Smash. He transforms and fights before the screen cuts back to a new character, Kengo Ino, at the press conference. He says for peace to come, Kamen Riders must become extinct and the crowd chants extinction. He uses his ability to manipulate the civilians who fall silent and begin walking off different directions, entirely noiseless. Build defeats the two Smash when groups of civilians appear, charging at him and engulfing him.

He manages to sneak out of the crowd and is chased throughout town, even getting back to the Cafe and is attacked by Sawa and Misora. He releases some gas in the lab and hides in the Fullbottle purification machine until they’re knocked out.

The three governors have a meeting with Evolto and reveal themselves to be the Blood Tribe, survivors of the same race as Evolto who aim to destroy the planet and consume it. It is also revealed that they had been acting in the shadows ever since the Skywall appeared and manipulated each territory during the war until Evolto changed his mind and their plans were disrupted. Evolto tells them he won’t interfere but reminds them he has the upper hand with the power of the Pandora Box.

Ryuga is picked up in a limo after visiting his girlfriend’s gravestone. Mitsuomi, the Zebra Lost Smash, appears in the limo, causing Ryuga to jump out from the car. They then both transform and fight. Mitsuomi reveals that he was the one who ordered Kasumi to be turned into a Smash. Ryuga loses the fight and is becomes controlled like the other civilians.

Sento infiltrates a lab and discovers that the three governors are the other astronauts from the Mars mission. He is discovered and chased again by civilians before running into Kazumi and Gentoku, who transform to help hold them for Sento to escape. Ryoka appears before them and transforms into the Scissors Lost Smash. Sento gets away as Kazumi and Gentoku are captured. Sento then meets Ryuga and Kengo. After fighting, Ryuga beats Sento and takes the Hazard Trigger. Kengo absorbs Ryuga along with the Scissors and Zebra Lost Smash, then uses the Hazard Trigger, Cobra Lost Fullbottle and Great Cross-Z Dragon with Ryuga's Build Driver to become Kamen Rider Blood. He easily defeats Sento, but before he can deal the final blow, Evolto appears and takes Sento away.

Sento wakes up on a boat with Soichi in the rain. They talk and Sento leaves, visiting the alley where Evolto pretended to find him without his memories. In his mind, Sento talks with Takumi about the events leading up to this point, This includes the fact that the Rider System was one of the biggest causes of the war, which is a thought Sento keeps struggling with. Takumi argues that to win, Sento has to kill Ryuga, which Sento disregards.

Later, Utsumi offers to break Kazumi and Gentoku out of captivity if they beg. Kazumi refuses, but Gentoku gives in. Kengo contacts Sento and demands the Pandora Box in exchange for Ryuga’s life. Ryuga, Kengo, Mitsuomi and Ryoka are outside, surrounded by civilians under their control. Sento arrives on his bike with the Pandora Box. Kengo becomes Kamen Rider Blood and Sento transforms into Build Genius Form. Kengo reveals that his encounter with Ryuga was orchestrated. They fight and Sento recalls one of Takumi's memory's in which his father told him that Ryuga holds the key to all the events to come. Takumi then asked why he became a scientist and his father replied "For love and peace". Sento manages to pull Ryuga out of Blood. Blood takes the Pandora Box down into the ground, heading for the center of the Earth so that he can destroy the planet. Gentoku and Kazumi appear and fight the Scissors and Zebra Lost Smash. Misora uses her powers to free Ryuga from Kengo’s control. The Gold Rabbit and Silver Dragon Fullbottles fuse into the Cross-ZBuild Can. Sento and Ryuga use it to transform into Build Cross-ZBuild Form.

They head down to fight Blood, and while they initially struggle to control their new form, they force Blood back to the surface and defeat him with the Love & Peace Finish. Kazumi and Gentoku win their respective battles. The humans under the Blood Tribe's control forget about what happened and Sento is a bit disappointed that no one knows what they went through.

In a post-credits scene, Sento is working on the White Pandora Box panel when it suddenly opens up a bottle that engulfs him. He is teleported to an outside location and overhears fighting over the side of a cliff. All of the Heisei Riders are there fighting their respective final villains. Zi-O arrives in the Time Mazine. Sento and Zi-O briefly talk and Zi-O comments how he already has Build’s power. He uses the Build Ridewatch and jumps off the cliff, transforming mid-fall. He fights the villains before using the Vortex Time Break.

Continuity and Placement

 * Kamen Rider Build: This movie takes place shortly after the announcement of the three new governors in episode 45. . The post-credits scene with Zi-O's cameo takes place during the events of episode 46, shortly after the creation of the White Pandora Panel and before Sento's mental conversation with Takumi.
 * Kamen Rider Zi-O: The post-credits scene takes place some time after episode 2, since Sougo is in possession of the Build Ridewatch and indirectly implies he knows Sento's identity.

Allies

 * Misora Isurugi
 * Sawa Takigawa
 * Vernage

Other

 * Shinobu Katsuragi (flashback)
 * Nariaki Utsumi

Villains



 * Terror Dopant
 * Uva
 * Kazari
 * Gamel
 * Mezool
 * Kyoryu Greeed
 * Scorpion Zodiarts
 * Cancer Zodiarts
 * Virgo Zodiarts
 * Leo Zodiarts
 * Sagittarius Nova
 * Evolved Gremlin
 * Lord Baron
 * Heart
 * Brain
 * Medic
 * Gamma Ultima Ebony
 * Gamedeus

Cast

 * Sento Kiryu (桐生 戦兎): Atsuhiro Inukai (犬飼 貴丈)
 * Ryuga Banjo (万丈 龍我): Eiji Akaso (赤楚 衛二)
 * Kazumi Sawatari (猿渡 一海): Kouhei Takeda (武田 航平)
 * Misora Isurugi (石動 美空): Kaho Takada (高田 夏帆)
 * Nariaki Utsumi (内海 成彰): Yuki Ochi (越智 友己)
 * Sawa Takigawa (滝川 紗羽): Yukari Taki (滝 裕可里)
 * Takumi Katsuragi (葛城 巧): Yukiaki Kiyama (木山廉彬)
 * Gentoku Himuro (氷室 幻徳): Kensei Mikami (水上剣星)
 * Soichi Isurugi (石動 惣一): Yasuyuki Maekawa (前川泰之)
 * Evolto (エボルト): Tetsuo Kanao (金尾 哲夫)
 * Build Driver (ビルドドライバー): KORBY (コービー)
 * Sclash Driver (スクラッシュドライバー), Cross-Z Magma Knuckle (クローズマグマナックル): Norio Wakamoto (若本 規夫)

Guest cast

 * Kengo Ino (伊能賢剛): Masanobu Katsumura (勝村政信)
 * Mitsuomi Gobara (郷原光臣): Takashi Fujii (藤井隆)
 * Ryoka Saiga (才賀涼香): Rena Matsui (松井玲奈)
 * Shinobu Katsuragi (葛城 忍): Joji Kokubo (小久保丈二)
 * Kamen Rider Zi-O (仮面ライダージオウ): So Okuno (奥野 壮)

Suit Actors

 * Kamen Rider Build: Seiji Takaiwa (高岩 成二)
 * Kamen Rider Cross-Z: Eitoku (永徳)
 * Kamen Rider Grease: Satoshi Fujita (藤田 慧)
 * Kamen Rider Rogue: Jun Watanabe (渡辺 淳)
 * Kamen Rider Blood: Yasuhiko Imai (今井 靖彦)
 * Zebra Lost Smash: Hajime Kanzaki (神前 元)
 * Scissors Lost Smash: Yasuaki Ishii (石井 靖見)

Fullbottles

 * Bottle used:
 * Build
 * Biotic: Rabbit, Taka, Ninjya (in Drill Crusher), unknown bottle (in Build Phone), FullFull RabbitTank (Rabbit Mode), Gold Rabbit, Silver Dragon
 * Abiotic: Tank, Gatling, FullFull RabbitTank (Tank Mode)
 * Other: Hazard Trigger, Genius, Cross-ZBuild Can
 * Cross-Z
 * Biotic: Dragon Magma
 * Abiotic:
 * Other: Cross-Z Magma Knuckle
 * Grease
 * Biotic: Rose (in Twin Breaker)
 * Abiotic: Gatling (in Twin Breaker), Syoubousya (in Twin Breaker), Lock (in (Twin Breaker)
 * Rogue
 * Biotic: Crocodile Crack
 * Abiotic: N/A
 * Blood
 * Biotic: Cobra Lost
 * Abiotic: N/A
 * Other: Great Cross-Z Dragon, Hazard Trigger
 * Zebra Lost Smash
 * Shimauma Lost
 * Scissors Lost Smash
 * Hasami Lost
 * Form used:
 * Build
 * RabbitTank Form, RabbitRabbit Form, TankTank Form, HawkGatling Form, Genius Form, Cross-ZBuild Form
 * Cross-Z
 * Cross-Z Magma, Cross-ZBuild Form

Sclashjellies

 * Jelly used:
 * Grease
 * Robot

Evolbottles

 * Bottle used:
 * Cross-Z
 * Biotic: Great Dragon
 * Abiotic:
 * Other: Great Cross-Z Dragon
 * Evol
 * Biotic: Cobra
 * Abiotic: Rider
 * Other: Evol Trigger
 * Form used:
 * Cross-Z
 * Great Cross-Z
 * Evol
 * Black Hole Form (Phase 4: Perfection)

Ridewatches

 * Watch used:
 * Zi-O, Build
 * Rider Armor(s) used:
 * BuildArmor

Theme song
The theme song for the film is Everlasting Sky, performed by Beverly, who also performs the show's main theme song, Be the One. The chorus was first played at the press conference for the film and other subsequent press conferences for the film alongside .

Errors

 * Despite of the in-series setups for this movie (the evolutions of Rabbit and Dragon Fullbottles), the movie entirely ignores them, as the Fullbottles appear to be in their nomal state at the start of the film, and only evolve before the climax fight. However, the conclusion of the film explains why those Fullbottles are seen to evolve again at the end of the series.
 * Zi-O's Time Mazine came shooting down like a meteor instead of arriving from a time portal.
 * The Ziku Driver does not announce "Rider Time" before beginning the announcements for BuildArmor.
 * When Zi-O BuildArmor performs his Vortrex Time Break, the Ziku Driver stays stationary the whole time, with no sign of Zi-O ever turning it to activate it.
 * Zi Oh also can be seen (for unknown reason) hit Wizard during his finishing attack. It's unknown if this is an error during CGI or not