The Pet Girl of Sakurasou

 The first time he saw her, it was love at first sight. Unfortunately for Sorata Kanda, "she" was a cat named Hikari and his school's rules forbid keeping pets in the regular dorms. As a result, Sorata is banished to the infamous Sakura Hall alongside other troublesome and unusual students like Jin, overzealous playboy, Ryuunosuke, the reclusive hermit, and Mashiro, a brilliant artist who's so unfocused and clueless about the real world that dorm supervisor Ms. Sengoku assigns Sorata the task of taking care of her along with his ever-growing collection of stray cats!

(Source: Sentai Filmworks)