When the Hikari Studio appears in the World of Den-O, Tsukasa finds himself dressed in a strange detective-like attire with possession of a Rider Pass. He is then suddenly possessed by an Imagin, who battles a Mole Imagin as Kamen Rider Den-O. After taking out the Imagin, the possessed Tsukasa walks off until Natsumi uses her pressure point move to drive the Imagin out of him. When the Imagin known as Momotaros tries to possess Tsukasa, again, he throws Yusuke in front of him and Yusuke becomes possessed. After easily overcoming M-Yusuke and treating him to pudding for answers, Tsukasa learns that the Imagin lost his physical form some time before they arrived. The possessed Yusuke then runs out of the Hikari Studio to go after the other Mole Imagin with Tsukasa and Natsumi close behind as they look for the DenLiner to solve the mystery. However, Urataros, Kintaros, and Ryutaros possess Tsukasa and chase after Natsumi for answers. When Tsukasa forces the three out and they enter Natsum