Mika, who divorced her husband 10 years ago, raised Tatsuya with just one woman. He worked desperately not to make him feel pity because he was a single-mother family, and eventually Tatsuya graduated from graduate school and was offered a job offer. At the same time as the child-rearing had settled down, I lost my goal and felt emptiness. One day, Tatsuya invited me to a hot spring trip, saying, "Thank you for letting me go to graduate school." Mika and Tatsuya set out on a graduation trip alone ...