Keitaro Urashima is the only boy living at the Hinata House, an all girl-dorm. Despite fact that he's kind of a screw-up, the girls are climbing all over each other in an effort to tear his clothes off. But it's not what he thinks! Supposedly somewhere on his body is a map to Hinata's secret treasure!
An already tumultuous living situation escalates into an uproar when Keitaro and the girls must entertain a group of guests, as their dorm transforms back into a hot springs inn. Things keep going wrong and the customers have crazy ideas of their own!
Join the gang on a wacky adventure which reveals the true mystery of the old annex!