Nakitai Watashi wa Neko wo Kaburu

Summary

Miyo "Muge" Sasaki is a peculiar second-year junior high student who has fallen in love with her classmate Kento Hinode. Muge resolutely pursues Kento every day, but he takes no notice of her. Nevertheless, while carrying a secret she can tell no one, Muge continues to pursue Kento. Muge discovers a magic mask that allows her to transform into a cat named Tarou. The magic lets Muge get close to Kento, but eventually it may also make her unable to transform back to a human.

(Source: Anime News Network)