Cho Kamen Rider Den-O & Decade Neo Generations: The Onigashima Warship

Cho Kamen Rider Den-O & Decade NEO Generations The Movie: The Onigashima Battleship (劇場版 超・仮面ライダー電王＆ディケイド ＮＥＯ ジェネレーションズ 鬼ヶ島の戦艦) is the fourth film adaptation of the popular Kamen Rider Series Kamen Rider Den-O, following Kamen Rider Den-O: I'm Born!, Kamen Rider Den-O & Kiva: Climax Deka, and Saraba Kamen Rider Den-O: Final Countdown. The Onigashima Battleship is the first of the films to be part of the Cho Den-O Series, a new multimedia franchise featuring the characters of Den-O and many new characters. It opened in theaters on May 1, 2009.

Story
Taking place after the events of Kamen Rider Decade episode 15, under the impression that they saved the World of Den-O, Tsukasa Kadoya and company begin their journey to the World of Kabuto when they are halted by Sieg who presents them a manuscript that detailed the legendary Oni Conquest with Momotaros' image on it. As this occurred, the Tarōs mysteriously vanish from the DenLiner as they are about to help Kotaro Nogami out with the true threat to their world.

Meanwhile, in the year 1980, a boy named Yu encounters Mimihiko and then Yu is possessed by Deneb who gets him away from the Gelnewts before New Den-O arrives to cover his escape. Deneb then brings Yu to Ryotaro, revealing Mimihiko to be one of the Oni of legend and is searching for the Trump Stone which Yu possesses. Seeing Yu reluctant to give them the item, Ryotaro leaves him with a DenLiner admission ticket should he change his mind. The next day, Yu runs off after learns that his father wants him to leave with him. Learning he is hunted by the Gelnewts, Yu tries to outrun the monsters on his bike before managing to reach the sands of time where the DenLiner is waiting for him. Giving them the Trump Stone, Yu wishes to be remain on the train. Though Owner warns him their intent to go back in time to fight the Oni, Yu refuses to turn back. After Yu is informed on the effects the distortions had on Ryotaro and Yuto, the former regressed to a child while the latter has mysteriously disappeared, the DenLiner arrives at the Junction Point where they meet the Station Master who reveals a 1936 newspaper revealing that Urataros, Kintaros, and Ryutaros are making a living as rice thieves in the bodies of another trio named Jiro, Ramon, and Riki (the Arms Monsters of Kamen Rider Kiva). During that time, the kids find Tsukasa who offers his aid. Kotaro is reluctant to accept his help until Tsukasa reveals the scroll Sieg brought with him that has Momotaros on it.

Arriving in the Muromachi period, DenLiner gang arrive and defeat the Gelnewts, meeting Toki and joining her at the village's pleas. Once at Onigashima, New Den-O and the villagers catch the Gelnewts off guard as the kids find Momotaros. Deneb asks Yu to form a contract with him, at least until Yuto returns, to be able to assist the others in. Den-O and Deneb join the fray as Kuchihiko arrives and assumes his Rider form Goludora. During the fight, Toki takes a hit meant for Yu before New Den-O is defeated. Using Kotaro as a bargaining chip, Goludora gives them a day to accept his demands for both the Trump Stone and the DenLiner. The next day, after planning it out, the DenLiner gang gives up both the Trump Stone and the DenLiner. Once the Owner and Naomi are evicted, Kuchihiko ditches Kotaro as he enters the DenLiner to reach his brother in the present time period. However, his journey is staged as the evicted "Owner" is the Station Master in disguise as the real Owner pulled the emergency break as everyone else has erected a massive set designed to look like modern Tokyo. Once the DenLiner staff and the Station Master enter the train, with Kohana guarding the door, Den-O, the Tarōs, and New Den-O battle Goludora and the Gelnewts with Toki providing backup, until she is wounded in battle.

However, Diend appears long enough to summon Kamen Riders Ohja, G3 and Caucasus as wild cards in the fight and Kuchihiko reassembles the Oni's Trump Stone with Mimihiko activating the Demon's Warship in the present and using it to return to the past. The Oni Brothers are able to defeat them until Tsukasa and Sieg arrive, allowing Den-O to assume Wing form as Momotaros possess Tsukasa to fight as Decade. The other Tarōs do the same with Diend's summoned Riders (Urataros with G3, Kintaros with Caucasus and Ryutaros with Ohja) while Deneb enters Kotaro, enabling Kamen Rider New Den-O to assume Vega Form. Helping Toki fire her arrow, Yu manages to break the Demon's Warship’s anchor to give the Kamen Riders time to set up a way to end the fight. At Decade's suggestion, Ryotaro forms Kamen Rider Den-O Super Climax Form with the Tarōs and Sieg. Cho-Den-O and Decade manage to overwhelm the Oni Brothers with New Den-O Vega Form and Teddy's aid. After Shilubara sacrifices himself to protect his brother, an enraged Goludora enters the Warship and engages the DenLiner in a battle with Decade taking his leave as the DenLiner gang manages to sink the Warship from the inside out as Kamen Rider Den-O Sword finishes Goludora off with a Rider Kick. Soon after, Yu bids farewell to Toki as she is revealed to be his ancestor. Though offered a slight detour before they return to present, Yu turns it down as he wants to be back in his time. After they part ways, Deneb is dropped back in 2009 where he finds Yuto waiting for him, where he reveals that he went by the name Yu as a child and they return to the ZeroLiner.

Pre-production and casting
Initially scheduled to be released in April 2009, Toei later announced that the film would be included in the new Cho Den-O Series. The first new cast member to be announced was gravure idol Akina Minami. The cast members of Den-O to return include the voice actors of the Tarōs, Sieg, and Deneb, as well as the actors portraying Naomi, Kohana, and Owner, among others (Toshihiko Seki, Kōji Yusa, Masaki Terasoma, Kenichi Suzumura, Shin-ichiro Miki, Hōchū Ōtsuka, Rina Akiyama, Tamaki Matsumoto, Yuichi Nakamura, and Kenjirō Ishimaru). Also to be featured in the film are several cast members of the current Kamen Rider Series Kamen Rider Decade and some of the cast members of Kamen Rider Kiva who are possessed by Tarōs.

Movie-exclusive Kamen Riders
The movie's antagonists are the two Oni Brothers of Onigashima, who both use the Gelnewt (ゲルニュート) Mirror Monsters as their foot soldiers.

Goludora
The eldest of two Oni Brothers, Kuchihiko (クチヒコ) has the ability to become the grasshopper-like Goludora (ゴルドラ) and is armed with a Khakkhara as his weapon.

Shilubara
The younger Oni Brother, Mimihiko (ミミヒコ) has the ability to become the dragonfly-like Shilubara (シルバラ) and is armed with a kanabō as his weapon.

Rider Cards

 * Cards Used:
 * Kamen Rider Decade:
 * Kamen Ride: Decade
 * Attack Ride: N/A
 * Form Ride: N/A
 * Final Form Ride: N/A
 * Final Attack Ride: Decade
 * Forms:
 * Decade
 * Kamen Rider Diend:
 * Kamen Ride: Diend, G3, Caucasus, Ouja
 * Attack Ride: N/A
 * Form Ride: N/A
 * Final Form Ride: N/A
 * Final Attack Ride: N/A
 * Forms:
 * Diend

Cast

 * Kotaro Nogami (野上 幸太郎): Dori Sakurada (桜田 通)
 * Tsukasa Kadoya (門矢 士): Masahiro Inoue (井上 正大)
 * Daiki Kaito (海東 大樹): Kimito Totani (戸谷 公人)
 * Toki (トキ): Akina Minami (南 明奈)
 * Yu (ユウ): Ruka Sawaki (沢木 ルカ)
 * Naomi (ナオミ): Rina Akiyama (秋山 莉奈)
 * Natsumi Hikari (光 夏海): Kanna Mori (森 カンナ)
 * Ryotaro Nogami (野上 良太郎): Takuya Mizoguchi (溝口 琢矢)
 * Kohana (コハナ): Tamaki Matsumoto (松元 環季)
 * Jiro (次狼): Kenji Matsuda (松田 賢二)
 * Ramon (ラモン): Yuuki Ogoe (小越 勇輝)
 * Riki (力): Eiji Takigawa (滝川 英治)
 * Yuto Sakurai (桜井 侑斗): Yuichi Nakamura (中村 優一)
 * Kuchihiko (クチヒコ): Eisuke Sasai (篠井 英介)
 * Mimihiko (ミミヒコ): Shingo Yanagisawa (柳沢 慎吾)
 * Owner, Station Master (オーナー、駅長): Kenjirō Ishimaru (石丸 謙二郎)
 * Eijiro Hikari (光 栄次郎): Renji Ishibashi (石橋 蓮司)
 * Chiyoko Shimizu (清水 千代子): Tomiko Ishii (石井 トミコ)
 * Yasushi (ヤスシ): Shoma Yashiro (矢代 奨馬)
 * Akira (アキラ): Kiyotaka Yamada (山田 清貴)
 * Kenji (ケンジ): Oki Fujimoto (藤本 旺輝)
 * Anglers (釣り人): Taro Suruga (駿河 太郎), Yuta Owada (大和田 悠太), Kenzo Ryu (笠 兼三)

Voice actors

 * Momotaros (モモタロス): Toshihiko Seki (関 俊彦)
 * Urataros (ウラタロス): Kōji Yusa (遊佐 浩二)
 * Kintaros (キンタロス): Masaki Terasoma (てらそま まさき)
 * Ryutaros (リュウタロス): Kenichi Suzumura (鈴村 健一)
 * Deneb (デネブ): Hōchū Ōtsuka (大塚 芳忠)
 * Sieg (ジーク): Shin-ichiro Miki (三木 眞一郎)
 * Teddy (テディ): Daisuke Ono (小野 大輔)
 * Gelnewt (ゲルニュート): Nobuyuki Hiyama (檜山 修之), Kōsuke Toriumi (鳥海 浩輔)
 * Decadriver, Diendriver (ディケイドライバー、ディエンドライバー): Mark Okita (マーク 大喜多)

Suit actors

 * Kamen Rider Den-O/Momotaros, Kamen Rider Decade: Seiji Takaiwa (高岩 成二)
 * Kamen Rider New Den-O, Deneb: Makoto Ito (伊藤 慎)
 * Urataros, Kamen Rider Diend: Eitoku (永徳)
 * Kintaros, Goludora: Jirō Okamoto (岡元 次郎)
 * Ryutaros: Toshihiro Ogura (おぐら としひろ)
 * Deneb: Yoshifumi Oshikawa (押川 善文)
 * Sieg: Naoki Nagase (永瀬 尚希)
 * Teddy: Shinichi Kaneda (金田 進一)
 * Shilubara: Norihito Ito (伊藤 教人)

Songs
Theme song
 * "Cho Climax Jump" (超 Climax Jump)
 * Lyrics: Shoko Fujibayashi
 * Composition & Arrangement: Shuhei Naruse
 * Artist: Den-O All Stars (電王オールスターズ): Momotaros (Toshihiko Seki), Urataros (Kōji Yusa), Kintaros (Masaki Terasoma), Ryutaros (Kenichi Suzumura), Teddy (Daisuke Ono), the Owner (Kenjirō Ishimaru), Kotaro Nogami (Dori Sakurada), Naomi (Rina Akiyama), and Kohana (Tamaki Matsumoto)

Note

 * The way that DienDriver announce "Kamen Ride" is different from the television.
 * Garulu, Dogga and Bassha were briefly possessed by Urataros, Ryutaros and Kintaros in the 1930s whom ironically they are very similar to.