A white ermine Okojo-san lives at an exotic pet store run by a greedy manager, until he escapes one day. In the chaos following, he ends up unconscious in a garbage can, where college student Haruka Tsuchiya finds him. Mistaking him for a ferret, Tsuchiya takes Okojo home with him. At the Shiawase apartment complex, Okojo meets other pets, including the mouse Chorori, and the various eccentric human tenants. With his friends, Okojo struggles to adapt to life with humans, vacuum cleaners, and all the other things that come with human society.