Miki, who divorced 10 years ago, has been raising Naoya single-handedly. Naoya graduated from university and secured a job. However, despite his commute taking over an hour, Naoya refused to leave the family home. Moreover, he didn't go out to play on weekends, nor did he bring friends or lovers back home. Concerned, Miki suggested that he should go out more often and invited Naoya on a hot spring trip.
