Haruka Mikami is an ordinary female student.
Her grades have not been good recently, and her parents, worried about her, take the liberty of asking her to have a private tutor.

The tutor, Masaya Reisenin, is a legendary teacher.
The monthly fee was so high that he could never afford to pay it.
However, Haruka is pleased to learn that she can make up the shortfall elsewhere.
She was delighted to learn that Masaya would teach her classes, and her grades improved in the blink of an eye.

Then came the day to pay the monthly fee.
Masaya demanded that Haruka, who had forgotten about the shortfall, pay it with her body.

Haruka’s resistance is futile, and she is subjected to sex education.