Kamigami no Akuma

A mysterious man butchers his way through a busy train car in Tokyo. This marks the starting point of a series of mysterious incidents. Renji Amamiya is attacked by Toriko, a prostitute with whom he is in love with, but he is saved by father Mitakura, a renowned exorcist who reveals to him the existence of demons...

(Source: Nihon Bungeisha, translated)