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Several years after the tragic event in 1989, Akira Yuki plots his revenge in taking on the most monstrous nuclear menace known to mankind-Godzilla! However he's not the only one whose targeted the King of Monsters. The intergalactic tyrant SpaceGodzilla has also aimed his sights on Godzilla! Not only that, but the entire world as well! Two Godzillas, one earth, who will remain and hold the crown?
Ryoma Nagare, Hayato Jin, and Prof. Saotome pilot three specially designed combat jets, which can be combined together in different forms to form three different kinds of giant robots, Getter-1 (used for aerial combat), Getter-2 (for land-based conflicts), and Getter-3 (for undersea battles). They were assembled by Prof. Saotome and became Earth's first line of defense against the Dinosaur Empire, which is a civilization of reptile-like humanoids, who evolved from the now-extinct dinosaurs that roamed the earth millions of years ago.
One day, an unidentified monster suddenly came out of a volcanic crater near Mt. Fuji, and was given the name "Vulcanus". Lava spews out of its entire body, and as it grows and evolves, the enormous beast's body leaves nothing but scorched earth along its path... Then it makes it to the capital city of Tokyo. Meanwhile, Ichiro Ichinose is a 39-year-old bachelor whose dreams have been shattered and now simply spends his days meaninglessly. After attending a classmate's wedding ceremony, he happens to reunite with his childhood friend Kanata Aida, but after she tells him something that he couldn't possibly understand, the beast arrives and things quickly take a turn for the worse...
Six-graders Boco, Junichi and Joe were enjoying their summer vacation. It was strangely rainless summer, but other than that, it was just like another summer. Three boys knew it was their last summer together. Same summer, deep inside a mine tunnel in New Guinea, an investigation team found something. No one knew they were creatures...terrifying creatures.
Something monstrous rises up from the sea and nearly sinks a Japanese fishing boat. The sole survivor tells a tale that no one wants to believe. But when a Russian nuclear submarine is destroyed in the same waters, the world is forced to face the truth: Godzilla has returned!
An old Hayato leads the Saotome Research Facility, which has developed the Getter Robo Hien to combat a new force which threatens the Earth: large plantlike monsters.