Jûzô Murasaki is a child miscast in his classroom, being often abused, tortured, beaten as well as degraded by the bully Tôru Akai and also his gang of juvenile punks. After years of repression, being rejected as well as worry without dealing with Akai, he creates a crazed dual personality with a terrible alter-ego. While staying in the apartment 13 of a tenement building, he ends up being unable to manage his violent dark character, that plots a bad revenge against his top flooring next-door neighbor Akai as well as his family members.