A new life begins after his father's remarriage. Yoshio finds himself completely captivated by his new stepmother, Misa—a stunning, lustful woman—so much so that he forgets about his daily routine. Misa shocks everyone around her by openly indulging in bold, uninhibited masturbation, even in broad daylight, without caring who might see. Unable to view her as just a mother figure, Yoshio's emotions grow increasingly turbulent.