A ship runs aground on a mysterious atoll leading to an investigation by insurance representative Kusanagi, who discovers an ancient bead that he gives to his daughter Asagi. Meanwhile, ornithologist Nagamine investigates reports of a new species of large bird named Gyaos. As the Gyaos begin to attack, an ancient guardian with a bond to Asagi emerges.

As a massive alien craft heads to Earth to do evil, three good and powerful superwomen befriend a young boy who has a special connection to Gamera. The alien Zanon launches a battery of familiar foes against Gamera, who might have to give the ultimate sacrifice to defeat the alien invader.

When a giant stone statue on Wester Island is disturbed, the legendary monster Jiger appears and heads for Japan. Gamera tries to stop this new rival, only to be injured when Jiger lays eggs inside of him. As two boys in a submarine go on a dangerous quest inside of Gamera's body to save him, Jiger threatens the Expo '70 world's fair in Osaka.

An atomic explosion awakens Gammera, a giant fire breathing turtle monster from his millions of years of hibernation.

An ever evolving alien life-form arrives on a comet from the Dark Gaseous Nebula and proceeds to consume pollution. Spewing mists of sulfuric acid and corrosive sludge, neither humanity nor Godzilla may be able to defeat this toxic menace.

Two years after the murder of his son and father, a retired hitman sets in motion a carefully crafted revenge plan against the killer: his own brother.