The boy in the mountain village was happy. When he was young, his mother fell into a trap and died in order to prevent poachers from poaching. Father ran away from home again, so far no news. The change of the family makes the happy and lonely character rarely communicate with others actively, and he has been with the monkey king "Great Saint" in the forest for many years. Years later, the improvement of the environment and the return of wild animals caused the greed of poachers. The film tells the story of being happy to lead the little friends and the monkey king "Great Saint" and the poachers to fight together with wisdom and bravery in the familiar forest.