Nozomi divorced her husband 10 years ago and raised Naoya on her own. She worked hard so that Naoya would not feel sorry for being a single parent, and before she knew it, Naoya was old enough to graduate from college. With child-rearing coming to an end, Nozomi felt relieved, but at the same time, she felt a sense of emptiness that she had lost her goal. Then one day, Naoya invited her on a hot spring trip. Nozomi and Naoya set off on their graduation trip just the two of them.