The Kougami Foundation has developed a new verse system "Birth Driver X" as a countermeasure against the resurrected Greed. However, during the wearing experiment, the wearer, Shintaro Goto, disappeared. The energy supplied to the driver went out of control and Goto was sent to a parallel world. In that world, Izumihina was fighting as Kamen Rider OOO...!? Situations that make the bewildered Goto even more baffled occur one after another. Goto, who wants to return to his original world at all costs, will be saved by Eiji, Greedo, or the mysterious "Doctor"!? "Phantom debut match".