Sakura Mizuki

A young widow, Noriko, lives with her senile father-in-law on a farm. Noriko pretends to be his long-gone favorite cow and lets him milk her—a satisfying arrangement for them both.

Tatsuji, the protagonist, is a retired high school teacher living a quiet life of leisure. With time on his hands, his only pleasure is eavesdropping on his son and daughter-in-law’s sex life. One day, a former student named Kana visits him and declares, "Teach, have sex with me!" To think he’d be giving a girl like her a "private lesson" in bed...