Masao, a son, lost his father when he was young and has lived with his mother, Yoshimi. Masao secretly considers his mother to be of the opposite sex, and harbors a faint wish that they could just live together like this... One night, when Masao returns home, he sees Yoshimi, who was supposed to be late at a class reunion, in her room with a man. The two seek each other without realizing that they are being watched, and their frustration oozes over it.