Keitaro Urashima is somewhat of a failure. In order to fulfill a promise he made to a girl fifteen years ago, he has tried time and again to get into Tokyo U but has never managed to pass the exam. However, fate smiles upon him and he ends up working for his aunt, managing an all-girls dorm! Living with the feral Kaolla, the timid Shinobu, the sake-loving Mitsune, the blade mistress Motoko and the punch-happy Naru, can Keitaro keep his focus and keep his promise? And will he ever end up meeting that girl from his past?