Due to an error the male student Kagami Yuuki is registered for a room in the girls dormitory of his new co-ed high school. Since no male rooms are available he is left with no other option than to sleep in the girls dormitory in the same room as the teacher that made the mistak in the first place, Ayane-sensei. To avoid getting kicked out of the school for being a boy in a girls dormitory he has to cross-dress whenever he is leaving his room. Needless to say that this brings him a lot of trouble.

Summary of the first season of the show, as seen from Rikka's perspective with new elements.

Yuuta and Rikka are in their third year of high school. One day in Spring, Touka declares that she will take Rikka to Italy with her, as her job has stabilized there and thinks they should migrate together as a family. Touka is also worried about Rikka not being competent enough to advance to universities in Japan. The gangs from the club suggested Yuuta, who doesn't want to be separated, to elope with Rikka!! A runaway drama throughout Japan begins.