In this adult mother-son role-play, Kenji is the undemanding middle son of three brothers. One spring, his older brother leaves for work, his younger brother enters a boarding school and their father takes an assignment away from home, leaving Kenji alone with his mother, Sae. The once-busy house falls silent and she struggles with the loss. Hurt that she seems preoccupied with his brothers, Kenji grows determined to claim all of his mother's affection for himself, drawing them into an incestuous life together.