Misae Sagara is the dormitory manager for the all-boys dormitory where Youhei Sunohara lives. She is a former student of Hikarizaka Private High School, where she served as the first female student council president and was widely admired for achieving a full week of perfect attendance for the entire student body. In her current role, she is generally friendly and approachable with the dorm residents but enforces the rules strictly. She is also well-liked by the school's rugby team members, though she does not hesitate to use physical discipline, including martial arts skills or a broom, when students become too rowdy or neglect their cleaning duties.

Her background includes a significant romantic relationship during her high school years. She met a boy named Katsuki Shima, who insisted on granting her a wish as thanks for encouraging him to recover from an illness. Misae was initially reluctant, but over time their feelings deepened, and rumors about their relationship helped her win the student council presidency. However, Katsuki Shima was not a human boy but a cat that had been entrusted with a mission by a dying boy named Katsuki Shima to grant Misae a wish. The cat took human form to fulfill this duty. When Misae finally made her wish—that Katsuki would love her forever—the cat returned to its original form and continued to stay by her side. Misae, unaware of its true identity, adopted the cat as her pet and spent years waiting for her human lover to return.

Misae's primary motivation is loyalty and patience. She remains devoted to the memory of Katsuki Shima, hoping he will come back, while unknowingly caring for the cat that is actually him. Her strictness as a dorm manager stems from a sense of responsibility and a desire to maintain order, and she is willing to become physically forceful when necessary. In the story, her past is gradually revealed through a dream sequences triggered by the cat, and eventually Tomoya Okazaki informs her of the cat's true nature during a town festival, bringing her emotional closure.

Her key relationships are with Youhei Sunohara, whom she often scolds for being messy and noisy; with Tomoya Okazaki, who becomes a friend and the one who helps her uncover the truth; and with her cat, which is the reincarnated form of her lost love. Misae's development involves moving from a long, patient wait to gaining understanding and acceptance of the love that has been with her all along. Notable abilities include her martial arts proficiency and her history as a capable student leader, which translate into her authoritative yet caring presence as a dorm manager.