Frankenstein vs. Baragon
Throughout WWII, Germans acquire the never-ceasing heart of Frankenstein's monster as well as transport it to Japan to stop it being seized by the Allies. Kept in a Hiroshima lab, it is seeming lost when the USA destroys the city with the atomic bomb. Years later on, a wild kid is discovered straying the streets of the city alone, birthed of the never-ceasing heart.