Kyouhei, after moving away to Tokyo from his old town to get away from the events that happened, is on a goukon with his friends, including his old neighbor, Shiba. After drinking for a whole night, he and Shiba discover a dead, bloody body in the elevator. He is told by his younger sister, Utao with her Kamisama Doll, that Aki, an old friend, and his Doll are the culprits responsible.

[Source: MyAnimeList]