Emi's grandson Kota, worried about her husband who has been living alone in the countryside, decides to visit her for the first time in a long time. "We used to take baths together when we were little. Today, I'll wash your back. Show me how much you've grown." Emi, who had been feeling lonely, is happy to take a bath with him. There, she sees his young, rock hard cock and becomes aroused for the first time in a long time. It turns out that Kota still doesn't know anything about women...