Since her husband left home, Reiko has devoted herself to raising her son Daisuke alone, choosing to raise him in an overprotective manner. As a result, Daisuke remains a shut-in, completely dependent on Reiko. However, Daisuke doesn't mind this situation at all—deep in his heart, his love for Reiko, who raised him with such care, has taken firm root. One spring, Reiko wins a pair of tickets to a hot spring trip in Izu at a local shopping district raffle. Seizing this chance, hoping a change of scenery might bring about some transformation, Reiko suggests taking Daisuke along on the trip.