"We're moving tomorrow..." With the graduation of their only son Akira, Hotaru and Akira move in with their husband when he is away on a business trip. Hotaru and Akira are busy cleaning the house they've lived in for many years. The bathroom is especially special to them, as it was when Akira lost his love... or when he got muddy from club activities... The two have always exposed themselves to each other in their birthday suits. And before they knew it, this relationship had turned into a forbidden one... That night, the two take their final bath. In the midst of all this, Hotaru tells Akira something...