It is the near future, in the 100th year of Showa (year 2025). The population of world is more than 10 billion, and a world-class space development project called "Mars Terraforming Project" is in process. One day, a spaceship "Izanami" crashes in Japan on the way from Mars, and it revives the monster Negadon, which was captured by the spaceship. Can the human race knock down the monster !? Under the desperate situation, a middle age man Ryuichi Narasaki rises up against the monster. He is a robotics expert who lost his daughter in an accident during his experiments. Now, the desperate struggle between Narasaki and Negadon begins!!