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.
After a convenience store robbery, three unidentified men hold a group of people hostage in a hospital. Inspector Ishida and Captain Tohno handle the negotiations while one of their colleagues, Lt. Ando, tries to find out why the men decided to take the hospital hostage. Through flashbacks, relevant information is revealed to the audience. When the negotiations are finished, most things seem to be fine until they lose track of the criminals. Then, the story unveils from a different perspective, its roots in feelings of love and vengeance.
