Mother wears a leotard and diligently does daily exercises. When her son returns home, she asks him for a massage, and he immediately complies. However, the son's mind is filled with secret, lustful fantasies about his mother. He murmurs, "Just looking at my mother's lewd body makes me more and more aroused." Though the mother is exasperated by her perverted son's behavior, she gradually becomes unaware that her own pussy is leaking slippery fluids. At that moment, the forbidden boundary between them collapses, and they plunge into a new, taboo world.