After her daughter got married and moved out last year, Reiko lived alone. However, two months ago, her daughter invited her to move in, and Reiko began living with her daughter and son-in-law. Though she felt grateful toward the couple, she also felt lonely—and at night, hearing them having sex stirred a deep ache in her body, leaving her sexually frustrated. One day, while her daughter was out and her son-in-law stayed home with a sore back, Reiko offered to give him a massage. Her skilled hands aroused him instantly. Realizing what she had done, Reiko felt responsible—and slowly reached out to touch him.