Ten years ago, Shiori divorced her husband and raised Taiichi on her own. Taiichi safely graduated from university and got a job at a printing company. However, since it takes more than an hour to commute, Shiori suggested that Taiichi live alone, but Taiichi did not want to leave home. Moreover, he didn't go out to play even on his days off, nor did he bring friends or girlfriends over. Shiori became worried and decided to take him out sometimes, inviting him on a hot spring trip.
