In the year 2025, mankind begins its triumphant expansion into space. But when a returning spaceship crash-lands on the streets of Tokyo, it unleashes a deadly cargo: Negadon, a giant, vicious monster from beneath the surface of Mars! Now, only Dr. Narasaki and his long-abandoned robot Miroku can save the Earth. In a clash of titans that will shake the planet to its core, it's giant robot versus space monster for the fate of all mankind!