Yui Ogura has harbored a deep, unrequited love for her older male relative, a man she calls her brother despite them not being blood siblings. Her world collapses when he announces his marriage to another woman. At the wedding ceremony, Yui encounters a sobbing boy named Kaoru Naruse. It soon becomes clear that Kaoru is weeping for the same reason: the bride is his own cousin, whom he had been in love with. The two heartbroken young people share a moment of mutual sympathy, then part ways.

Determined to move on and find a new love, Yui enrolls in a school and moves into a student dormitory, only to discover that the dorm is exclusively for boys. Worse, the head of the dormitory is none other than Kaoru. Forced to live under the same roof as the boy who shares her romantic misfortune, Yui must navigate the awkwardness of their shared history while trying to open her heart to new possibilities. The close quarters of the all-boys dorm, populated by a cast of eccentric male residents, create a chaotic and comedic environment. As Yui and Kaoru are repeatedly thrown together, their initial mutual wariness gradually gives way to a tentative connection, complicated by lingering feelings, misunderstandings, and the presence of other interested parties such as Koujirou Mikamida. The story follows their bumpy journey from two people wounded by love toward a potential new relationship, all while living in the same unconventional dormitory.