In the Tokugawa Era, the clan of Lord Yagyu has hidden away three scrolls containing clan secrets which, if revealed, would cause revolution and disaster for the clan. The information is divided among the three scrolls, all of which must be possessed for the secrets to be understood. When Princess Yuhime steals the scrolls, Tasaburo, a samurai with magical powers, and his brother Senshiro are sent to retrieve them.

Japan is thrown into a panic after several ships are sunk near Odo Island. An expedition to the island led by Dr. Yemani soon discover something far more devastating than imagined in the form of a 50 meter tall monster whom the natives call Gojira. Now the monster begins a rampage that threatens to destroy not only Japan, but the rest of the world as well.

The advertising director of Pacific Pharmaceuticals, frustrated with the low ratings of their sponsored TV program, seeks a more sensationalist approach. He orders his staff to Faro Island to capture King Kong for exploitation. As Godzilla re-emerges, a media frenzy generates with Pacific looking to capitalize off of the ultimate battle.

A burning Godzilla, on the verge of meltdown, emerges to lay siege to Hong Kong. At the same time horrifying new organisms are discovered in Japan. These crustacean-like beings are seemingly born of the Oxygen Destroyer, the weapon that killed the original Godzilla.

Mining engineer Shigeru investigates the disappearance and death of his fellow coworkers when prehistoric nymphs are discovered emerging from the mines. After an attack on the local village, Shigeru heads deeper into the mines only to make a more horrifying discovery in the form a prehistoric flying creature. Soon a second monster appears as the two converge in Fukuoka.

During an assignment, foreign correspondent Steve Martin spends a layover in Tokyo and is caught amid the rampage of an unstoppable prehistoric monster the Japanese call 'Godzilla'. The only hope for both Japan and the world lies on a secret weapon, which may prove more destructive than the monster itself.

A submarine expedition to salvage the remains of Mechagodzilla is thwarted by a massive dinosaur named Titanosaurus. An Interpol investigation leads biologist Ichinose to uncover the work of Dr. Mafune and his mysterious daughter Katsura. Aligned with the Black Hole Aliens, Katsura's life becomes entwined with the resurrected machine.

Reporter Goro Maki stumbles upon scientists conducting weather experiments on Sollgel Island in the South Seas. He discovers the island is inhabited by giant mantis and a woman named Saeko who's been cast away since the death of her father. The pair soon find a helpless infant monster that Godzilla must adopt and learn to raise as one of his own.

When a rare species of butterfly is found in a mysterious valley in Japan, a pair of entomologists go to investigate and find more. They discover Varan, a giant monster, who decides to leave the valley and head straight for Tokyo.

A re-edited Italian-language dubbed version of Godzilla, using as a basis the U.S. version Godzilla, King of the Monsters! (1956), plus WWII newsreel footage and clips from other monster 1950's movies. The re-edited film was then colorized via a process called Spectrorama 70 consisting of applying various colored gels to the black and white footage. The film's opening and ending also features new music composed by musician Vince Tempera (under the pseudonym Magnetic System).

An Okinawan prophecy that foretells the destruction of the Earth is seeming fulfilled when Godzilla emerges to return to his destructive roots. But not all is what it seems after Godzilla breaks his ally Anguirus's jaw. Matters are further complicated when a second Godzilla emerges, revealing the doppelgänger as a mechanical weapon.