Photon Earth is a young, gentle boy possessing superhuman strength, with "Baka" (Japanese for "idiot") scribbled on his forehead, apparently by his troublemaking friend Aun Freya. One day, he finds himself engaged to the beautiful fugitive pilot Keyne Acqua after writing "baka" on her forehead. This is merely the least of his worries, as he must protect both Aun and Keyne from the evil Papacharino, who seeks to steal the secrets of "Aho" (another term for idiot) energy from Keyne's grandfather's ship.