This movie is an alternate ending to the series, taking place after the events of episode 46. With only six Riders remaining in the Rider War: five of the six, Ryuki, Knight, Zolda, Ohja, and Femme, Shir? Kanzaki alerts them to quickly settle the Rider War within three days. One of them must win and become the last survivor before the sixth surviving rider reveals himself. Amidst the impending chaos of the fight between the Riders, Shinji discovers an unbelievable truth about the relationship between Yui Kanzaki and the Mirror World, as well as discovering the existence of his Mirror World doppelganger, Kamen Rider Ryuga.