Reiko, who lost her husband and raised her son Ichiro alone. Naturally, she was frustrated every day, but one day she found an erotic book about her mature woman in her son's room. Reiko finds out that her son is excited about a woman of her age and she has an indescribable feeling for her son. And by witnessing her son's masturbation and her morning erection, Reiko's desires are limited.
