Mirai Shōnen Conan

In the 21st century, 20 years after World War 3, the world as we know it has been destroyed. Conan lives on an island with his grandfather, believing they are the only two survivors. Conan discovers a fleeing girl named Lana on the beach. After Lana is kidnapped from the island, Conan decides to rescue her and sets sail to Industria.