Hina Fujisaki is a 38-year-old mother. One day, she sneaks into her son's room and catches him hastily hiding something. When she takes it from him, she discovers it's a porn magazine. Furious at seeing her son once again watching adult videos instead of studying, she scolds him. Suddenly, the boy collapses on the floor, claiming he has a stomachache. However, the pain clearly seems to be coming from his crotch, and the mother sees through his act. Years later, the lingering effects of that incident continue to shape the complex relationship between mother and son, leaving one wondering what the future holds.