Ever since her daughter and son-in-law started living with her, Miu has been plagued by sexual frustration. It's been a while since her husband passed away, and whenever she hears the sounds of her daughter and son-in-law having sex at night, her crotch throbs. Miu's fingers aren't enough to satisfy her, so she starts hiding her lower body in the kotatsu and comforting herself with vegetables. One night, her son-in-law comes home from work and falls asleep in the hallway. Miu wakes him up and takes him to the kotatsu. He's drunk and staggering about. He's always found Miu sexy, so he pushes her down and they have sex. The next morning, they talk about what happened the night before and decide to continue their relationship without telling their daughter...