12 years ago, the Daybreak Town Accident changed the world and brought forth a new prosperity towards artificial intelligence. But what if that were to all change? Sougo Tokiwa gave up his conquest for power after he chose to reset the world and live a mundane life. However as a Time Jacker began to alter history once again, Sougo is forced to take up the mantle as Kamen Rider Zi-O once again, as he meets Aruto Hiden, the native Rider of the world he has to save. This is the story of two Kamen Riders from two different worlds, whose fight together will ultimately determine the fate of all reality.