Kagami Yuuki has always wanted to a scholarship to the prestigious Houri Academy. However, due to a mistake by a teacher, Kakinozaka Ayana, he ended up in the Academy's girls' dorm! Further, the situation cannot be corrected, and Yuuki must live and dress as a girl if he wishes to study at Houri. And if his secret should be revealed, he would be instantly expelled.
To make up for her error and to assist Yuuki in his deception, Ayana-sensei offers to be his room-mate.