Mukushina Kokoro

She is a serious person who wears a uniform and is the school council president where Aoki transferred to.
Despite her strict personality, she is popular among both men and women.
She is especially popular among the boys, partly because of her strange and lewd behavior when she eats.

However, when she is alone and out of the public eye, she is rather careless.
If she is not careful, her tongue tends to loll out on its own.

Her true identity is that of a ghost, Youkai.
She likes to clean up the grime in the men's restroom.

When the main character comes to do his business, he witnesses the scene and has relations with her in order to keep her appearance in the school without saying a word.