Every day, her son fondles his mother Reiko's voluptuous breasts. Though she still saw him as a child, Reiko gradually becomes aware of his feelings. Knowing their mother-son relationship makes this improper, she tries to reject him, but her son won't stop. One day, while Reiko is bathing, her son suddenly attacks her, instantly crossing the boundary between mother and child. Overwhelmed by her son's vigor, Reiko begins to feel emotions she's never experienced before. Before long, she starts anticipating his touch and the way he gropes her. Their mother-son bond slowly transforms into something far more intimate...