Keiichi Noda

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 ...

A giant sea monster known as Dragonsaurus has emerged from out of nowhere, terrorizing the depths of the oceans. Great Mazinger, Grendizer and the Getter Robo G team join forces to combat the new threat. But their task becomes more complicated when Dragonsaurus swallows up Boss Borot and makes its way towards Tokyo. Source: ANN

A moon base is destroyed by a spaceship from Zigra which is looking to take over the planet earth to use its oceans for its ocean-dwelling denizens. Gamera must once again come to the aid of the human race while all of Japan roots him on.