Masao, a son who lost his father at a young age, has been living with his mother, Yoshimi. Secretly aware of his mother as a member of the opposite sex, Masao harbours a faint wish that the two of them could continue living together like this... One night, when Masao returns home, he witnesses Yoshimi, who will be late at a class reunion, in her room with another man. The two are unaware that they are being watched, and Masao is filled with regret. "If my mother is going to become someone else's, then I'd rather just..."