Conan is the only child of a group of refugees marooned on an island after humanity almost wiped itself out during World War III. When the show begins, he is living on the island with the last of the survivors, a man he calls "Grandpa".

Since Conan has been diving and fishing his whole life on the island, he can hold his breath for a very long time underwater. He carries a spear around with him that he uses to fight and catch fish with. Conan is also very strong, and uses his toes in many unorthodox ways. He uses his feet almost as often as his hands.

Conan is something of a wild boy since he grew up living only with his grandfather for human contact, but he is a kind person with an honest heart. He is especially very gentle with Lana, a girl who he befriends.