Tsukasa travels to his home world of the World of Decade, where he discovers the origin of his powers and his true heritage as the leader of Dai-Shocker. The film features all ten of the lead Heisei Kamen Riders, as well as all of the Shōwa period Kamen Riders, leading to a total of 25 Riders.

Kamen Rider Decade: All Riders vs. Dai-Shocker

After the wild murder of an idol with great scissors, a young woman will acquire the certainty that the legendary lady with a torn smile is responsible for this bloodbath. Accompanied by a friend (who possesses the soft peculiarity of always wandering in miniskirt and sometimes show her panties), she will soon be confronted with the monstrosity made woman ... to the detail that this time the kuchisake onna Maybe no longer alone ...