The film Kamen Rider Decade The Movie: All Riders vs. Great Shocker (劇場版 仮面ライダーディケイド オールライダー対大ショッカー ) is to open in Japanese theaters on August 8, 2009, double-booked with the Shinkenger film.
The film is promoted to feature a total of 26 Kamen Riders: the original 10 Showa Riders, BLACK, BLACK RX, Shin, ZO, J, the previous 9 Heisei Riders, Decade, and Den-O.
The film also provides light to Tsukasa's memories due to Decade's relation with the mysterious Great Shocker organization, whose membership is composed of the various villians and monsters that previous Kamen Riders battled with. Moe Arai (荒井 萌 Arai Moe) portrays Tsukasa's younger sister Sayo Kadoya (門矢 小夜 Kadoya Sayo). Ryuichi Oura (大浦 龍宇一 Ōura Ryūichi) portrays Nobuhiko Tsukikage (月影 ノブヒコ Tsukikage Nobuhiko) who transforms into Shadow Moon. Tetsuo Kurata and Toshiki Kashu return to portray Kotaro Minami and Shouichi Tsugami. Hiroshi Fujioka, Takeshi Sasaki, and Hiroshi Miyauchi also return to respectively voice Kamen Rider 1, Kamen Rider 2, and Kamen Rider V3.