A ronin son, overwhelmed by the stress of exam season, loses control around his mother. Determined to get into college this year, he has been living an ascetic life, but grows increasingly sensitive to his mother's constant nagging to "study harder." Normally her presence is irritating, but now her voluptuous figure excites him—her full breasts, her thick thighs—making him hard and turning her into the object of his masturbation. His arousal won't subside. Unaware of her son's inner turmoil and frustrated by his lack of progress, the mother pushes him further, cornering him in desperation. In a shocking turn, the son lashes out and attacks her, depicting a disturbing, incestuous tension that erupts between mother and child.