When several T.V. satellites launched by the Electric Wave Laboratory go missing above Japan in Earth's orbit, people later discover that they inadvertently collided with unidentified protoplasmic "space cells" of unknown origin. A similar creature suddenly thwarted the efforts of a local branch of the International Diamond Robbery Ring. The diamonds they sought vanished, and similar unexplained events continued to occur across the globe.
Meanwhile, Inspector Komai's (Yosuke Natsuki) investigation of these strange events leads him to the crystallographer Dr. Munakata (Nobuo Nakamura). While tracking down the self-proclaimed diamond broker Mark Jackson (Robert Dunham), he finds him in Dr. Munakata's home but knocks him out and escapes from Komai. The gangsters then pick him up for questioning. Komai wakes up, and Dr. Munakata and his lab assistant Masayo Kirino (Yoko Fujiyama) greet her. He tells them about the case he is working on and shows them pictures of the melted safe the gangsters were at that night. Komai then learns that the diamonds the Mark stole were synthetic and worthless.
The gangsters bring Mark Jackson to their boss and find a bag containing the stolen diamonds; however, they learn that they're fake and keep him as a prisoner, but Mark outwits them and escapes. The gangsters then receive word of a shipment of raw diamonds that will arrive in Yokohama. Meanwhile, Inspector Komai escorts Masayo to her home. Along the way, they meet Kirino (Hiroshi Koizumi), Masayo's brother, who works at the Electric Wave Laboratory. They witness a strange invisible force suck up coal into the sky from a nearby factory as well as flaming sparks from the clouds. They meet back with Dr. Munakata, who tells them that the flaming sparks might be from some form of carbon. Later, the professional thieves take advantage of this opportunity and attempt a heist on an armored car carrying the raw diamonds. But an unknown force lifts a nearby passing coal truck off the ground. It disappears into the atmosphere and falls back down to earth. Unfortunately for them, they were fooled and escaped with nothing but candy.
The police came to learn of the mysterious events of the armored car heist. Inspector Komai tells them of the possibility of a creature that caused the coal truck to list up in the air, but no one believes him. Masayo then calls him and tells him that Mark Jackson is at Dr. Munakata's house. Komai and the police surround the place to catch him. But he reveals himself that he is an investigator dispatched from the World Diamond Insurgence association to find out what has been stealing diamonds worldwide. Just then, Masayo's brother comes in and tells them that the Space Planning Committee at the U.N. reported the monster's identity as a space cell mutated by massive amounts of radiation from the satellites. Suddenly, Dogora appears and eats its way through Dr. Muanakata's safe to eat the diamonds inside.
The people deem Dogora to be the culprit, an alien beast that draws its energy from carbon-based minerals. Dr. Munakata, confident in a remarkable scientific discovery, left for the coal mines near northern Kyushu, where they proposed the strange being would make its next appearance. Mark Jackson also took leave for Kyushu, realizing that the candy recovered at the heist was likely his doing. It was probable that he had, in truth, absconded with the real gems. Hamako (Akiko Wakabayashi), one of the gangsters responsible for the failed heist, prepared to double-cross her comrades and retrieve the diamonds for herself.
As Dr. Munakata arrived at Dogora's next likely target, unidentified objects began to show on radar. In retaliation for the disturbance of their hives in the mines, a swarm of wasps attacked Dogora, and as they attacked, solid crystal sections of the monster began to fall to the city below.
As night fell over Dokaiwan Bay, evacuation orders went into effect as the jellyfish-like monster descended from the sky. The self-defense force fired, to no avail. The beast continued to absorb carbon-based materials wherever it could find them, and the abomination even destroyed the Waikato Bridge in the process. The military continued to unleash their artillery at the alien creature and succeeded in momentarily silencing their foe. Unfortunately, the beast was only undergoing mitosis. They later discovered that when Dogora is stung by the wasps, the venom causes a chemical reaction that crystallizes the space cell. Analysis of the crystallizing effects of the wasp venom on Dogora at the Medical Substance Laboratory proves successful. They soon ordered mass production ordered worldwide to create a similar toxin.
Still desperate for a successful heist, the gangsters tracked Mark Jackson and Inspector Komai and almost immediately jumped to conclude that Mark hid the real diamonds in a safe-deposit box. Hamako left to retrieve the stash but instead fled solo with the stolen goods. The thieves left Jackson and Komai tied and doomed to death-by-dynamite, but the two men joined forces and barely managed to escape.
Meanwhile, Dogora attacked once again, but this time, potent artificial wasp venom quickly ate away at the creature. The robbers and the police clashed at the beach, and in the heat of a vicious gunfight, the gang was utterly wiped out by a falling crystal boulder, once a section of Dogora's extraterrestrial flesh. The wasp venom finally took full effect, and Dogora was no more. The diamonds Hamako retrieved from the safe-deposit box were later discovered to be synthetic. As this truth came to light, Dr. Munakata and his secretary left for the U.N. to discuss the peaceful potential of the Dogora incident with the world.