In his younger years, Keitaro Urashima vowed to a girl that they would meet again at Tokyo University one day. Unfortunately, Keitaro ranked 27th from the bottom in the National Practice Exam, hindering his chances of attending Tokyo U. To pursue his dreams, Keitaro intended to reside at his grandmother's hotel, only to find out that it had metamorphosed into a women-only dormitory. Surprisingly, Keitaro became the dorm's manager and set off on a journey of living with five other girls.