Seiji Takeda waits all day for his girlfriend Touka Miyashita who never shows. In the evening a pale zombie-like man stumbles through the crowd, and is saved from falling by someone dressed as Boogiepop, whom Takeda recognizes as Touka. The next day at school, students are told of 4 girls who have gone missing and to be on guard. Seiji eventually finds Touka dressed as Boogiepop who reveals that she has a split personality, and that Touka has no knowledge of her Boogiepop persona which has surfaced to save humanity...