At Suimei High, the Sakura-sou dormitory serves as a home for the school's most challenging students. Sorata Kanda, a fairly ordinary boy, is transferred there and initially hopes to escape as quickly as possible. While residing in the dorm, he must adjust to life with eccentric roommates: Misaki Kamiigusa, a passionate animator; Jin Mitaka, a charismatic novelist; and Ryuunosuke Akasaka, who seldom ventures outdoors. Amidst these peculiar individuals, Sorata frequently seeks solace from Nanami Aoyama, his seemingly normal friend and aspiring seiyuu.
The arrival of Mashiro Shiina, a foreign exchange student, captivates Sorata with her striking beauty. However, beneath her enchanting exterior lies an autistic prodigy—a gifted artist who struggles with daily living tasks. As Sorata assumes the role of caretaker for Mashiro, their connection deepens, and his desire to leave the dormitory fades away.
Every resident excels in their respective field, leaving Sorata feeling mediocre by comparison. Despite feeling overshadowed by their talents, he strives hard to match their remarkable abilities. Centering on the struggles and triumphs of its vibrant cast, Sakura-sou no Pet na Kanojo presents a touching narrative about growth, friendship, romance, and heartbreak, viewed through the perspective of an ordinary person surrounded by extraordinary circumstances.