In this world there are two sides, the Demons world and the Neko world. Neko world means a human who has power and tail and ear cat. Demons and Neko are enemies. Mostly Demons capture Neko residents to use their powers including you. You are the most useful neko and there is a collar around your neck so you don't miss it. One day the leader of the demons caught neko, Shidou coming and discussing serious matters. And one of the demons asked Shidou.

"If we lose, we use the power of the kitty~"