Dynamic Super Robots Grand Battle

The year is 20XX. Mysterious huge robots called "Giant Robo (GR)" started to appear all over the world and destroy cities. The earth was covered with fear. And their next target is Japan! The hero of this animation Daisaku Kusama, who works in a diving shop, encounters a mysterious girl, simply called V who leads him to make a contract with an enormous robot "Giant Robo 1 (GR1)" at the ancient ruins (Minami Yonaguni Island) in Okinawa. He made a contract with UNISOM (main organization) and was approved to be a commander of GR1. Thus his battle has begun against GRO (antagonist organization) and creates a lot of dramas. Before long, Giant Robo of the 21st century will ask the world the true meaning of its power.

From the island of Bardos in the Aegean Sea comes a new threat to humanity in the form of Doctor Hell and his army of mechanical beasts. However, a new hero stands in his way: Mazinger Z, a giant robot built out of the indestructible metal chogokin and equipped with an arsenal of advanced weaponry. Piloting Mazinger Z is hotheaded teenager Kouji Kabuto, who strives to avenge the death of his grandfather and protect Japan from Doctor Hell's forces.

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.

From the far end of the universe, the terrifying space monster Gilgilgan attacks the Earth. The Science Fortress Laboratory and the Saotome Institute both fight against this threat. Distracted by their rivalry, Getter Robo and Great Mazinger are forced to retreat from Gilgilgan's sharp fangs, but once they agree to work together they begin their combined attack!