Attack of the Super-Monsters

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.

The evil organization 'Black Ghost' attacked around the world, using dinosaur (plesiosaur) type giant robots, and the team of 9 cyborgs launched their quest for the Black Ghost's hideout. 009 meets a girl named Helena...

The story is set in modern times, but the twist to the story is that Mazinger is an ancient weapon of the gods, left on earth to battle the evil space gods who have returned to take over the universe.

The Kikaika (literally mechanization) Empire invades our solar system, and in a matter of moments they take over and convert Neptune, Uranus, Saturn, Jupiter,and Mars, and set their sights on Earth. However, one thing stands in their way. Earth's ancient protector and soldier of light, Eldoran. To fight this menace he gifts a 5th-grade class with 3 huge robotic dinosaurs, with the power to merge and form the giant robot Gosaurer, which they then can pilot and use to stop the Kikaika Empire's advances.