While aimlessly walking around after loosing his apartment in a fire, the homeless Shuichi met a girl in housemaid attire. Apparently, that girl was his younger sister separated from him after their parents' divorce. She offered him shelter. He accepted it of course... only to find out that they'll be living together in an all-girls inn managed by his sister. The boarders were against it, however, they granted him a month of probational stay after some twists and turns. And his cohabitation with the girls began.