Pai has a dilemma on her hands. She made her newly undead partner, Yakumo, believe that she was among the undead as well, and has just found out that she has probably been human all along. The two had gone off on a search to regain their humanity together, but this turn of events leads them to believe that evil forces are at work against them to wrangle Pai's family secret of immortality away from her. Moreover, Yakumo must now rely on Pai's ability to recall a long dead memory to restore his humanity, even though the evil demons of the world have at work to suppress her memory.