After being defeated by the Jurai Emperor and the Galaxy Police centuries ago, the monstrously powerful Super A-1 class criminal Kain was imprisoned in the subspace room of the GP's headquarters, never to be released. Kain escapes his bonds, destroys the GP space station, and travels back in time to take his revenge on Jurai's royal family. The Galaxy Police only has time to send a short warning, which Mihoshi and Kiyone intercept.