The story begins with a scientific expedition led by Dr. Kawajiri, who embarks on a journey to a remote Pacific island to study the native wildlife and gather scientific data. The team includes Dr. Kurosaki and their children, along with a documentary film crew.
During their expedition, the team discovers a large egg that belongs to a prehistoric creature. They decide to transport the egg back to Japan for further study, believing it could be a significant scientific discovery. However, taking the egg from its natural habitat triggers the wrath of the egg's parents, who are revealed to be giant, bird-like creatures with amphibious capabilities.
The giant creatures, known as Gappa, emerge from their island and embark on a destructive path to rescue their offspring. The Gappa wreak havoc on Tokyo and its surroundings, causing widespread panic and devastation. The Japanese Self-Defense Forces are mobilized to combat the threat and protect the city.
As the chaos unfolds, the human characters, including the expedition team and the military, must find a way to resolve the situation and ensure the safety of the Gappa offspring. They grapple with the ethical and moral implications of their actions, as well as the challenges of dealing with a seemingly unstoppable force (1967).
Director: Hiroshi Noguchi
Stars: Tamio Kawaji, Yôko Yamamoto, Yûji Odaka