The film Kamen Rider Decade The Movie: All Riders vs. Dai-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 Gekijōban Kamen Raidā Dikeido: Ōru Raidā tai Daishokkā?) opened in Japanese theaters on August 8, 2009, double-booked with the Shinkenger film. The film is billed as featuring twenty-six Kamen Riders: the original ten Showa Riders, Black, Black RX, Shin, ZO, J, the previous nine Heisei Riders, Decade, and Diend. It also features the first on-screen appearance of the 11th Heisei Kamen Rider: Kamen Rider Double. The film provides light to Tsukasa's past and Decade's relation with the mysterious Dai-Shocker organization, whose membership is composed of the various villains and monsters that previous Kamen Riders battled with.
