Neighbour No. 13 (2005)

Original title: 隣人13号

What if your personality began to crumble… who would you become?

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.