Leo, a Galápagos sea lion pup, lives in a colony on the Galápagos Islands, ruled by a beachmaster, the lone adult Galapagos male sea lion in charge of a group of mother Galapagos sea lions and their pups. During Leo's childhood, his mother Luna teaches him how to swim. As Leo grows older, the beachmaster exiles Leo from the islands, forcing him to find a new home. Years pass, he tries and fails to find a new forever home, while temporarily coming across other exiled Galapagos sea lions and hungry Galapagos sharks. Going off on his journey solo, he finally claims an island of his own by banishing its beachmaster.