Rei and her husband have been married for 27 years. Rei works at a beauty salon, and her husband, Yoichi, has raised two children together as a busy Ministry of Finance bureaucrat. Yoichi has 5 years until retirement. In the meantime, their eldest daughter, who had a student marriage, had a child. It is the long-awaited first grandchild. Taking this opportunity, they went on a long-awaited hot spring trip to discuss their future lives. On their long-awaited hot spring trip, the mature couple burned with passion.