After losing her husband, she began living with her daughter and son-in-law. Her daughter was five months pregnant, and she was eagerly awaiting the baby's arrival. Wataru, her daughter's husband, also seemed to be happily looking forward to the birth. However, one day, when she stepped out of the bath, she found Wataru standing frozen, holding her underwear. She tried to flee in panic, but seeing a man so aroused by her appearance unexpectedly excited her. And then, she was overwhelmed by Wataru...