Unable to bear the sight of his son Tatsuya on the verge of repeating the year, his father hires a private tutor. The private tutor, Sayuri, puts her body on the line to give a special erotic lesson to help the underachieving Tatsuya study. Thanks to that, Tatsuya is able to concentrate on his studies... And then, the day before the test, he has a special lesson to help him lose his virginity so he can get a good grade and avoid repeating the year and graduate...