While combing through the belongings of his recently deceased aunt, Matsuko, nephew Sho pieces together the crucial events that sank Matsuko's life into a despairing tragedy.

After the collapse of their relationship, Kiwako abducts the 6-month old child of a man she was having an affair with. Raising the child as her own, it is four years before the authorities catch up with her and the young child.

Jûzô Murasaki is a boy miscast in his classroom, being frequently abused, tortured, beaten and humiliated by the bully Tôru Akai and his gang of juvenile punks. After years of repression, rejection and fear without facing Akai, he develops a psychopathic dual personality with a violent alter-ego. While living in the apartment 13 of a tenement building, he becomes unable to control his violent dark personality, who plots an evil revenge against his upper floor neighbor Akai and his family.