A girl named Sango and her brother named Rango were found washed up on the shore of an island as newborns. They're adopted and taken in by Kangaskhan, who becomes their "mother" figure, and Sceptile, who becomes their "father" figure. The twins are cared for and loved by the both of them, becoming a part of the village of pokémon that inhabit the island. They grow up isolated and unaware of the world outside of the island. Their lives are peaceful and carefree until one day a stranger arrives...