In an alternate Japan, territorial street gangs form opposing factions collectively known as the Tokyo Tribes. Merra, leader of the Wu-Ronz tribe of Bukuro, joins forces with heavy-hitting gangster Buppa of Buppa Town. With Buppa's support, Merra aims to initiate a gang war between the Wu-Ronz and the Musashino Saru, and in a confrontation between the two attempts to kill Kai of the Musashino Saru. The inadvertent murder of Kai's friend Tera (a Musashino Saru member beloved by all Tribes since before their formation) leads to the joining of forces between all of the Tribes in an all-out war against Merra and Buppa.

Juzo Murasaki is a young man traumatized by his experience of bullying at school. He returns to his hometown and takes a job on a building site with his old nemesis Toru Akai. But Juzo's trauma has created a monster; he harbors a second personality, Neighbor No. 13, a vicious, brutal and disfigured character intent on exacting a painful revenge on his bully.