The Ark, having diligently and painstakingly saved countless worlds, finally reached retirement day. "Hey, Demon King, your days of slacking off on the throne are over. Hand over my retirement certificate!" "If you want it, come and claim it yourself. You know the rules." The Ark had thought it would retire with honor, but never expected that the damn Demon King would scheme against it at the last moment. It accepted this "final" job: go to a new world and raise a new Oma Zi-O. "So, who have we got in mind? Who's going to be the new Oma Zi-O?" "No idea." "!!" "Then... which world are we going to choose the king from? You must at least know that, right?" "Not sure." "You son of a...!" In short, the Ark accepted this infuriating task, in which it had to choose both the world the king would come from and the king himself. It eventually arrived on the land of Terra. "So, who is worthy of becoming Oma Zi-O?" At last, the Ark turned its ill-intentioned gaze toward a certain black rabbit.