Azuma-kun no Koi Neko

Yamato is a 16-year-old boy and lives with his cat Kurume, who is estimated to be 11 months old. One night, while looking through a telescope on the roof of his school, Yamato sees his homeroom teacher, Shiina-sensei, crying and yelling at someone. At that moment, Yamato is overcome with emotions he doesn't understand, but Kurume is quick to notice Yamato's state... This is the story of Kurume, a cat depicted as a young girl, jumping into a new world.

(Source: Natalie, translated)