Maegami Tarou (1979)

This is a folk-tale-like adventure story of an active boy on a quest for the Water of Life. The boy sets out on this quest after learning that the Water of Life is needed to make his village happy. On the way, he meets gods, demons... Soon, he discovers that the evil snake has stolen the Water, and he heads for the snake's palace. Defeating the snake is not easy since it has the Water of Life to revive itself. This boy - Maegami Tarou - continues his courageous quest in cooperation with various creatures and the gods.