Tenkousei Jinno Murasaki

Jinnai Midori can get rid of evil spirits in people with his left fist. One day, a transfer student name Jinno Murasaki started to follow Midori around, claiming they were childhood friends. But Midori have no such memory. Midori punches Murasaki with his left fist of purification, but it doesn't work on Murasaki.