In Japan, there is a game called "Rabbit Doubt". The game is that all players are rabbits in the colony, and one of them is chosen randomly to be a wolf that penetrated into the rabbit group. In each round, the wolf kills the rabbit, and in every round the group is trying to figure out which rabbits is actually a disguised wolf. Sometimes children playing this game decide to meet personally, and Yuu, Mitsuki, Rei, Hadzhim, Eyji and Haruka did just that. Unfortunately, one of them decided to wear a wolf mantle and had already killed once. Who is such a wolf? Is it possible to stop them before everyone has a very unpleasant end?