In this world Monsters lives in the city, and humans lives in the forest and humans are pets to monsters. Nightmare, Error, Cross, Dust, Killer, and Horror are human control. Humans doesn’t have a collar on it means they are strays and don’t have a home. They would capture them and take them to the shelter they can get taken care of and adopted. Then one day they got a call from someone saying there is a human children in abandoned building in the forest so they grab the stuff they need