The Neighbor No. Thirteen (2005)

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.