After losing both parents, high school student Asahina Yuzu quits her old school to find a way to support her younger sister. A classmate, Fujiwara Ryuuka, steps in and arranges for her to work as a live-in dorm mother at his all-boys dormitory, Kourai Ryou, a building strictly off-limits to girls. To keep the job, Yuzu cuts her hair short and passes herself off as a boy in front of anyone outside the dorm. The residents all know she is female, and the arrangement works as long as no one else finds out.

Inside the dorm, Yuzu deals with a cast of distinctive and handsome residents. Ryuuka, the unofficial leader, is cool-headed around everyone except Yuzu, around whom he turns flustered and awkward. He has secretly been in love with her for some time. Another resident, Nikaidou Touto, initially declares he will not speak to Yuzu and tries to create distance, but he becomes increasingly involved in protecting her secret. Later arrivals, such as the easygoing Usui Tsubasa and the former delinquent Saotome Mirai, add further layers of personality and conflict.

Yuzu eventually transfers into the same high school as the dorm residents, where she resumes life as a girl by wearing a long wig and a uniform. Balancing her two identities—male dorm mother by evening, ordinary female student by day—she navigates school events, a cultural festival, and a sneaky date with Ryuuka. A love triangle forms when Touto’s cold attitude slowly thaws and he begins to show interest in her. The plot deepens as Yuzu and Ryuuka finally become a couple, though they have to keep their relationship hidden.

The later volumes focus on deepening the bond between Yuzu and Ryuuka, the arrival of new dorm members, a visit from Tsubasa’s childhood friend who does not know Yuzu is a girl, and a first overnight trip together. In the final volume, a major incident during a school trip threatens to expose Yuzu’s secret, forcing the group to rally together. The series concludes with Yuzu graduating from the dorm and her relationship with Ryuuka reaching a satisfying resolution.