Akira Himegami stands by Towasa, the AI prodigy who is both his adoptive sister and the woman he loves, until a gunman opposed to her ideals shoots them both at the shareholders' meeting where she is to unveil a breakthrough. Akira wakes from cryogenic sleep centuries later in a deserted laboratory, in a ruined city where civilization has regressed and the global organization OWEL controls access to old-era knowledge. Captured by OWEL and about to be executed, he is rescued by Yugure, an android with inhuman power who wears Towasa's face and asks him to marry her.