UFO Robot Grendizer vs. Great Mazinger
Alien invaders take over Great Mazinger who is at the entrance of a museum next to Mazinger Z as symbols of peace. Grendizer fights the evil invaders and Great Mazinger is recovered. When the Vegan empire dispatches a new general to oversee the takeover of Earth, he quickly manages to capture Koji Kabuto and, learning of Great Mazinger through interrogation, quickly commandeers it from a museum where it was kept as a symbol of peace. It is now up to Duke Fleed aboard Grendizer to stop humanity's former defender from becoming its destroyer.
- Genre: Animation, Action, Adventure, Science Fiction
- Director: Osamu Kasai
- Cast: Kei Tomiyama, Joji Yanami, Hiroya Ishimaru, Chiyoko Kawashima, Kazuko Sawada
- Country: Japan