Mika, who divorced her husband 10 years ago, raised Tatsuya by herself. He worked desperately not to make him feel sorry for him because he was a fatherless family, and eventually Tatsuya graduated from graduate school and got a job offer. At the same time that his child-rearing had reached a stage, he lost his goal and felt emptiness. One day, Tatsuya invites him to a hot spring trip to thank him for letting him go to graduate school. Mika and Tatsuya left for a graduation trip alone...
