Saraba Kamen Rider Den-O: Final Countdown

Taking place after the events of series, the Tarōs and Kohana go out of the DenLiner for a day to visit Ryotaro and Airi after their parting in the aftermath of their battle with Kai. However, they see the mysterious Ghost Train that has been mentioned in urban legends as Momotaros and gang are then attacked by two evil Imagin and Kamen Rider Yuuki Skull Form. During the fight, it is revealed to the Tarōs that Yuuki is none other than Ryotaro possessed by an evil Imagin. Even with Zeronos coming to the gang's aid, things seem bleak until a blue DenLiner appears with a new figure: Kamen Rider New Den-O.