Koi wa, Hitotsu Yane no Shita de…

Umi, a first-year high school student, is very fond of Ryu who lives next door and her childhood friend. She goes to the house next door to see Ryu every day. One day, unexpectedly Ryu decides to live in a boys' dormitory. Umi, who wants to be with him all the time, consults her aunt who is a manager of the dormitory. Her aunt suggests that Umi become an acting manager for ten days.