Neko to Mata

he series centers around two cats: a younger sister named Neko, and an older brother named Mata. Neko is a nekomata (a mythical two-tailed cat), innocently selfish, and spoiled by her brother. Mata is a neighborhood cat with an eartipped mark as a sign of being neutered. They meet under a streetlight in the city at night to talk.

(Source: Anime News Network)