One day, Masaru leaves school early and accidentally witnesses his mother Hisae masturbating in the bathroom. Overwhelmed by the sight of his mother's aroused, wet body, Masaru's heart races. After sneaking past her in the living room, he begins touching himself. His arousal spirals out of control as he dives into masturbation, only to be caught red-handed with his crotch fully exposed when his mother returns. Flustered, he tries to hide, but Hisae's eyes appear strangely dazed and entranced. Instead of scolding him, she does something far bolder than Masaru ever expected. The mother's unexpected reaction and the shifting emotions between them form the ultimate allure of this work.