In his usual form of a small black cat, Luo Xiaohei is a young monster who lives freely in the forests. However, due to deforestation and human development, he is forced to flee and search for a new home. Xiaohei wanders the city streets, struggling to survive until he meets Feng Xi, another monster, who takes him to a small island inhabited by a few monsters. Excited to have found a new home, Xiaohei's happiness is short-lived when Wuxian, a human Guild Executor, arrives on the island hunting for Feng Xi. When Feng Xi and his friends use their powers to teleport away, Xiaohei is left behind with Wuxian. Refusing to cooperate with a man who attacked his friends, Xiaohei is forced to travel with Wuxian to the Guild. During their journey, Xiaohei gains a new perspective on the ever-changing world and the relations between humans and monsters.