After losing her husband at an early age, Chisato Shoda raised her son alone. Now that he has grown into a fine young man and is about to get married, mother and son decide to go on a hot spring trip together. On the final day of their journey, they soak in the hot springs and enjoy a delicious meal, reflecting on how this might be their last trip together. At night, her son falls asleep, but she is awakened by his restless sleeping. As she tries to fix his futon, her eyes are drawn to his exposed lower body when his yukata slips open. His genitals look exactly like those of her late husband. Overcome with emotion, she can't resist and begins passionately sucking him. As her consciousness fades, she climbs on top of him, surrendering to the pleasure she hasn't felt in years...