Synopsis: After a Japanese town is totally destroyed, the military arrive to investigate. They encounter a giant robot that is decimating everything in its path. A dome appears out of the ground and a group of scientists are invited to meet the alien Mysterians from the planet Mysteroid. The Mysterians have come in peace, all they ask humanity for is three-square kilometers of land and the right to interbreed with Earth women to repopulate their species. Outraged at such a suggestion, humanity declares war on the Mysterians.