Metropolis (Kuroda Iou)

Kenichi, a 20-year-old man, took an entrance exam into college, but fails it for the third straight year. That day, he came across a traffic accident where it appeared that a giant robot went crazy and disrupted the flow of traffic. He meets a person by the name of Mitchy who is trying to save the remaining survivors. Who is this Mitchy person and what does this "Red Party" fraction have to do with the giant robot?