Minami lives happily with her beloved husband and daughter, but it has become a habit of masturbating at night without any help. And it was the same with his son-in-law, Tsuyoshi, who spent days comforting himself by looking at her. Minami, who is fascinated by his huge cock, makes his heart flutter and continues to seduce him every time. The son-in-law couldn't resist his mother-in-law's invitation, and one day the two of them had-for-tat day and night.