Aoran, a new student from the countryside, remembers that he forgot something while playing with his friends after school one day.

Aoki, who is a novice by nature unlike his burly appearance, is afraid to go to school at night and rushes back to his classroom to retrieve it.

As he is about to leave, he hears a suspicious sound in the hallway.

It was a ghost story he had heard when he first moved to the school: "In the middle of the night, you can hear the sound of something being piped, and if you hear it, you will die."

Aoki is so terrified that he has to urinate and runs to the school toilet.

There, he found his classmate, Kororo, is sitting in front of the men's toilet and licking the toilet, which was so long that it could not even be compared to a human being.

She then attacks him to get him silent about her being a "kurayame," a monster. Then, Hana, who came out of the private toilet room, yelling and leaning, also revealed herself as "Hanako-san, the flower girl of the toilet."