|This article is about a/an episode in Kamen Rider Decade.|
Rider War (ライダー大戦 Raidā Taisen) is the first episode of Kamen Rider Decade. It foreshadows the series' climax event and introduces several main characters and the setting. It also leads into the series' first two-part arc.
A young man named Tsukasa Kadoya learns of a war that involves all past Riders, and, as Kamen Rider Decade, he must protect their worlds, even if it means the destruction of his!
After Natsumi Hikari has a nightmare of every Kamen Rider including Kuuga in his fearsome Ultimate Form, being defeated by a figure called Decade, she helps her grandfather Eijiro deal with unsatisfied customers. The photographer, Tsukasa Kadoya, seems to be at fault, but he simply tells Natsumi the photos are bad because he does not belong in this world. After the argument, various holes in reality open, allowing the Orphnoch, Undead, Makamou, Worms, Imagin and Fangires to start terrorizing their world. In the bedlam, she finds a corroded belt and book, recalling it as Decade's from her dream. She gives Tsukasa the belt and book, allowing him to transform into Kamen Rider Decade by using a card from the book and inserting it into the belt. Using other cards, he fights the various monsters that have invaded his reality by transforming into Kamen Riders Kabuto, Faiz, and Hibiki. Back in his own reality, Tsukasa is warned by Wataru Kurenai that his reality is being superseded by the nine previous Kamen Riders' realities. He must go to their worlds and defeat the other Kamen Riders to save his own world, while Wataru keeps it frozen in place. Back in the Hikari Studio, Eijiro reveals a large photo that shows another world. Stepping outside, Tsukasa finds himself in this world as a police officer while Kamen Rider Kuuga appears to aid the police against two Gurongi.
- Card Used:
- Kamen Ride - Decade, Kabuto, Faiz, Hibiki
- Attack Ride - Clock Up, Auto Vajin, Ongekibou - Rekka
- Decade, Decade Kabuto Rider Form, Decade Faiz, Decade Hibiki
- Tsukasa Kadoya (門矢 士 Kadoya Tsukasa): Masahiro Inoue (井上 正大 Inoue Masahiro)
- Yusuke Onodera (小野寺 ユウスケ Onodera Yūsuke): Ryouta Murai (村井 良大 Murai Ryōta)
- Natsumi Hikari (光 夏海 Hikari Natsumi): Kanna Mori (森 カンナ Mori Kanna)
- Eijiro Hikari (光 栄次郎 Hikari Eijirō): Renji Ishibashi (石橋 蓮司 Ishibashi Renji)
- Decadriver Voice (ディケイドライバー音声 Dikeidoraibā Onsei): Mark Okita (マーク・大喜多 Māku Ōkita)
- Narration (ナレーション Narēshon): Eiichiro Suzuki (鈴木 英一郎 Suzuki Eiichirō)
- Wataru Kurenai (紅 渡 Kurenai Wataru): Koji Seto (瀬戸 康史 Seto Kōji)
- Ai Yashiro (八代 藍 Yashiro Ai): Hiroko Sato (佐藤 寛子 Satō Hiroko)
- Customer: Asami Ichioka (市岡 麻美 Ichioka Asami), Yu Imai (今井 優 Imai Yū)
- Gangs: Hirotaka Fujiyama (藤山 浩隆 Fujiyama Hirotaka), Tomokazu Koshimura (越村 友一 Koshimura Tomokazu), Arisa Tobita (飛田 有沙 Tobita Arisa)
- Ra-Dorudo-Gu (ラ･ドルド･グ Ra Dorudo Gu, Voice): Katsumi Shiono (塩野 勝美 Shiono Katsumi)
- End of the world
- Mirror Monsters: Hydragoons
- Orphnoch: Octopus Orphnoch, Okra Orphnoch, Pigeon Orphnoch, Dolphin Orphnoch, Rhinocerosbeetle Orphnoch
- Undead: Lizard Undead, Pecker Undead, Squid Undead, Caucasus Undead
- Makamou: Bakegani, Ittanmomen, Ooari, Ubume, Amikiri
- Worms: Culex Worm, Geophilid Worm, Sectio Worm, Sepultura Worm
- Imagin: Spider Imagin, Bat Imagin, Molech Imagin, Bloodsucker Imagin, Whale Imagin
- Fangire: Shark Fangire, Moose Fangire, Horsefly Fangire, Rat Fangire, Mantis Fangire, Seamoon Fangire
- World of Kuuga (Gurongi): Me-Gyarido-Gi, Ra-Dorudo-Gu
- Before Decade inserts Kamen Ride card of Hibiki to Decadriver, the Hibiki's symbol is already seen in there.
- Ongekibou - Rekka is immediately activated right after Decade transforms into Hibiki without the actual Attack Ride card being used.
- Onodera's Arcle Belt is activated before he could press the switch.
- As part of Super Hero Time, this episode aired alongside Engine Sentai Go-Onger episode 48, GP 48: Justice Dissolution.
- Viewership: 6.3%
- First-time Decade changes into Kabuto and Faiz.
- First and only time Decade changes into Hibiki in the television series.
- The Lords are the only one of the first nine Heisei Rider monster groups not to appear at all in this episode. The Gurongi appear at the end as part of the World of Kuuga, and all the others appear throughout the episode as the world is destroyed. This might be due to how they target specific humans and are otherwise their protectors.
- This episode is revisited among other Kamen Rider Series premieres in the video game Kamen Rider: Battride War Genesis.
Blu-ray Box comes with all 31 episodes.