Suddenly, the Gamedeus virus begins spreading through the streets! Masamune becomes Gamedeus Cronus and appears before the other Riders, as he summons Nico into the World of Kamen Rider Chronicle! Nico is the one who is qualified to challenge the Last Boss of Kamen Rider Chronicle as a Ride-Player, but it seems clear that Masamune is going to try to Game Over the player who is closest to beating the game in order to reset it. In an attempt to save her but unwilling to let the others follow, Taiga uses the Chronicle Gashats seized from patients and goes to find her. However, the other Riders cannot enter the World of Kamen Rider Chronicle! Just what will happen to Nico's fate?