Ragnarok (世界の国からこんにちは) 9 years old

This is the story of the future a little bit ahead.

The Japanese representative robot, demonstrated at the venue of the International Giant Robot Exhibition in Odaiba, goes out of control due to an unknown cause and destroys buildings around the venue. The police and Japan Self-Defence force cannot stop the robot, and the American and Russian robots are sent out to save the situation along with the request from Japanese government and the exhibition association office.