Sachiyo is a woman who greatly enjoys her sex life. While she often takes the initiative with her husband, she finds his selfish approach to sex leaves her unsatisfied. One morning, while entering her son's room to wake him before his prep school, she notices his father's erect d●ck and feels her heart race. Overcome by desire, she reaches out and grabs it. Responding to his mother's intense sexual appetite, the son crosses a boundary he should never have been able to, giving in to an unthinkable act.