Mother Yoko deeply dotes on her second son Jiro, an honor student preparing for exams, and her affection eventually reaches an extreme level, leading them into a physical relationship. Meanwhile, her troublemaking eldest son Taro discovers the affair and, consumed by jealousy and rage, threatens to expose his mother to their father, using the secret to blackmail her into submitting to perverse acts. His desires rapidly escalate, ultimately dragging his younger brother into the chaos, resulting in a shocking three-way incestuous relationship between mother and her two sons. This disturbing narrative explores twisted family bonds, the clash of forbidden love, and uncontrollable lust, depicting an abnormal and intense psychological drama.