A thief, a murderer, and a charming lady-killer, Iwao Enokizu is on the run from the police.
A strange meteor lands in Japan and unleashes hundreds of insect-like "Legion" creatures bent on colonizing the Earth. When the military fails to control the situation, Gamera shows up to deal with the ever-evolving space adversary. However the battle may result in Gamera losing his bond with both Asagi and humanity.
Rick, a down-and-out American boxer, is hired to transport a sword to Japan, unaware that the whole thing is a set up in a bitter blood-feud between two brothers, one who follows the traditional path of the samurai and the other a businessman. At the behest of the businessman, Rick undertakes samurai training from the other brother, but joins his cause. He also becomes romantically involved with the samurai's daughter.
