Hibiki, who raised her son on her own, sees a resemblance to her husband in the son who took care of him when he collapsed due to overwork, and they have a one-man relationship. - Three years have passed without incident, and now Hibiki is thinking about remarrying. - While he was hopeful that the three of them would be able to return to a happy life together, he also felt guilty about the mistake he made three years ago. - In order to sort out her feelings, Hibiki goes on a hot spring trip with her son.