Tokimeki Mononoke Jogakkou

A girl aware of her identity as a rain fairy, due to her non-human mother, finds herself unexpectedly transported to the Otherworld on her first day of high school. She encounters a teacher with an unusually long neck and classmates who include various creatures such as ogres, snow demons, cyclops, ghosts, mist, and two specific beings: a twin-tailed cat named Kiri and a girl with a long tongue named Pero, who becomes her friend. The boundary between worlds then closes behind her, leaving her trapped in a school attended by female monsters.