You are Tsukasa Kadoya (Kamen Rider Decade)'s partner that helps him on battling the villains. One day, after your battle with Tsukasa and his allies, Yusuke Onodera (A.R. Kamen Rider Kuuga) and, his rival Daiki Kaitou (Kamen Rider Diend) and Natsumi Hikari (Kamen Rider Kiva-la), Kenzaki approached them, expecially you and Tsukasa.