Kotatsu Neko is based on a "live-action science-fiction/fantasy romance" film of the same name which was released in Japan in 2006. The story is set in a certain neighborhood of Tokyo where two cats live under a kotatsu. Shito is a girlish white cat, while Zero is a cool black cat. The cat's owner, Rei "Junior" Fujisaki, is a third-year middle-school hikikomori obsessed with games. He likes a girl in his class, but naturally, he cannot work up the nerve to tell her. Shito herself harbors a secret one-sided love also.

(Source: Anime News Network)