Once upon a time, there was a world where humans and animals lived together. Mick, a traveling cat, and Choromaru, a squirrel, meet Penny, a boy who stole and was being chased by the police, in a city they stopped by one day. He was a member of "COINS", a group of children who were betrayed and abandoned by adults, but was betrayed by his friends and was in a predicament. Mick saves her in the nick of time, but Penny, who has lost her place, decides to go on a journey with Mick the cat and Choromaru the squirrel to find her true place!