Sumire, who lost her husband, decided to live with her daughter and son-in-law. They live together happily, but Sumire has one worry. That is, her daughter and son-in-law's nighttime activities. It's good that they get along well, but hearing her daughter's voice of joy every night makes Sumire feel anguished, and she spends many nights comforting herself alone. Sumire is curious about the lower half of her husband's body, which satisfies her daughter every night. One day, when her daughter goes out, she peeks into her husband's room and finds him masturbating. Sumire enters the room and calms the flustered husband, and then, saying "I'm sorry" even though he's in the middle of it, she reaches out to his lower half...