After divorcing her husband, Touko raised Yuki on her own. She worked hard because she was determined not to make her feel sorry for her, and she worked hard to pay for her tuition even after entering college. It was time for Yuki to get a job, and as soon as her parenting had settled down, she began to feel emptiness. At that time, she received an invitation from Yuki to take her on a trip to the hot springs, and she left for a graduation trip just the two of them.
