Nekota no Koto ga Ki ni Natte Shikatanai.

Amane Mikiko, known as Mikki, is an elementary student who frequently moves and must change schools. She often forms friendships only to have to leave them behind. At her new school, she resolves not to make any friends, but this proves difficult. She encounters a boy with a cat's head, though it's unclear if others see him the same way she does.