Wataru, a young, nerdy man who also narrates the film's story, uses some of his time to peep on his parents having sex, as well as on his sister, and is often seen masturbating to a porn magazine.

Masako, a widow, runs the local hot spring inn, Aku no Yu, all by herself. Her niece, Ritsuko, has been helping out at the inn since graduating from junior college in Tokyo. Her husband, Ikuo, died in an accident and was condemned to hell for adultery with Ritsuko, and his ghost roams the earth. One day, Kurio, who had been laid off and decided to commit suicide, arrives at the inn. Surprisingly, he looks exactly like Ikuo...