Mitarai Kouji, a college student living in a small apartment in Tokyo finds out his landlord and neighbors are all beauties. One day he spots one of them banging on his front door. Right as Kouji approaches her she immediately wets herself. Lending his shower and a change of clothes made her feel indebted to him. In return she said she would do ANYTHING. Jokingly Kouji says to pay him back with her body and she really does!