On Remnant Island, a tiny surviving enclave of humanity on the devastated Earth, Conan lives alone with his grandfather until a young girl, Lana, washes up on the shore. Two soldiers of Industria land their hydroplane and kidnap Lana. While threatening the intruders with a missile, Conan's grandfather is mortally injured when one of the soldiers opens fire on him, detonating the launcher.

After Lana is kidnapped by the two soldiers from Industria, Conan fails to rescue her. Conan's grandfather dies from his injuries. After burying his grandfather, Conan builds a boat and sets off to rescue Lana.