Godzilla vs King Ghidorah is the fifth Johnson Studios remake.
Police Detective Shindo is assigned to guard Princess Selina Salno of Selgina during the Princess' visit to Japan, due to a suspected assassination plot. Although Shindo is smitten with Selina's photograph, her plane never makes it to Japan, as it is destroyed by a bomb en route. At exactly the same time a meteorite shower draws the attention of Professor Murai, who along with his team of scientists strikes out into the wilderness to examine the largest of the meteors, which has magnetic properties.
To Shindo's surprise, the supposedly deceased Selina turns up in Japan, without her royal garb (including the golden bracelet which proves she is heir to the throne of Selgina), claiming to be from the planet Mars, and preaching to skeptical crowds of forthcoming disaster. To their surprise however, her prophecies begin coming true. First she predicts that the offpsring of the Rodan, thought dead in the eruption of Mt. Aso along with his parents, will emerge from Aso's crater. Subsequently, none other than Godzilla will arise from the sea and destroy a ship. Both of these events transpire.
In the meantime, Selina's uncle, who was behind the assassination attempt, learns of her survival and sends his best assassin Malness to Japan to dispatch the Princess and steal the golden bracelet. Malness and his henchmen are stopped by Shindo, who was warned of their attempt by the Shobijin, who were in Japan appearing on a television show. On said show, a pair of children get to meet the twin priestesses. They reveal that one of the Mothra Larva was killed by Varan in a last-ditch effort to stop their advance on Monster Island. The other is safe on Infant Island.
The Shobijin had been scheduled to return to Infant Island aboard the ship sunk by Godzilla, but opted not to go after overhearing Selina's prophecy. A further attempt by the assassins is thwarted when both Godzilla and Rodan attack the city and engage in battle, forcing everyone to flee.
In truth, Godzilla is not trying to kill Rodan, as Tom Stevenson of CBS believes is happening. Rather, Godzilla heard what Rodan did in Fukuoka in 1956 and, seeing him as a potential ally, decides to gauge his strength.
Convinced that Selina is insane, Shindo takes the Princess to see a renowned psychiatrist, Dr. Tsukamoto, in the hopes of curing her. However, Tsukamoto can find nothing wrong with her, mentally or physically. He concludes she must therefore truly be possessed by a Martian as she claims. As if emboldened by the doctor's diagnosis, Selina reveals her final prophecy—that Mars' once thriving civilization was destroyed by an evil, golden three-headed dragon named King Ghidorah (a member of a subset of t), and furthermore that Ghidorah himself has already arrived on Earth. No sooner has she revealed this than Professor Murai and his colleagues at the meteor crash site receive a nasty surprise—the "meteor" is actually an egg, which hatches into the fearsome King Ghidorah. Ghidorah begins razing the countryside.
To combat the combined threats of the three monsters, the Japanese government enlists the aide of the Shobijin to summon Mothra. Upon arriving on the Japanese mainland, Tom Stevenson arrives and reveals a technological marvel: a device that can translate monster talk! In the ensuing conversation, Mothra attempts to persuade the quarreling Godzilla and Rodan to team up against the evil alien but both refuse, with Godzilla stating they have no reason to save mankind as both he and Rodan "have always had trouble with men and men hate them" which Rodan agrees too. Besides, Godzilla still holds great hatred towards Mothra after he embarrassed him earlier in the year. Rodan uses his Uranium Beam on Mothra, which Godzilla is highly impressed by. The two agree to go smash San Francisco when Mothra is done babbling.
Despite Mothra stating that Earth belongs to them as well and that it is their duty to defend it, Godzilla and Rodan still refuse and the pair refuse to forgive humanity for its blunders with nuclear testing (which awoke them in the first place). Besides, Godzilla says, King Ghidorah could be a great asset to his "monster mafia". Unable to convince them and despite being vastly overpowered, Mothra calls the pair of them "bastards" and resolves to fight Ghidorah by herself. Mothra engages Ghidorah and is continually blasted by his gravity beams.
Godzilla ponders what Mothra has said, and what he said. Then he realizes something: King Ghidorah has caused more destruction in 2 hours than he could in a day. He also seems to take sadistic pleasure in killing people, whereas Godzilla doesn't really intend to harm people, but rather teach them an important lesson about the dangers of nuclear weapons and power. He comes to a conclusion: Ghidorah destroys to conquer, whereas he and his friends only do so for sport and territorial reasons. He also sees the light about humanity: they didn't intend to create him, and if it weren't for them, he wouldn't be where he is today, King of the Monsters. Godzilla makes an important decision to call off all hostilities with humanity and become its champion. Besides, Godzilla always felt a fondness for children. He sends Rodan as his messager to Monster Island to inform Anguirus, Varan, and Manda about their shifted alignment, while Godzilla heads off to fight King Ghidorah and redeem himself.
After returning from Monster Island, Rodan regroups with Godzilla and they arrive to help Mothra and a titanic battle against Ghidorah begins. Meanwhile, Shindo and Dr. Tsukamoto are forced to protect Princess Selina as Malness and his men converge on Tsukamoto's clinic; they fend the killers off and escape into the mountains as the dueling monsters draw closer, so they can watch the battle from a safe distance.
The assassins attempt to follow, but a stray blast from Ghidorah buries their car in an avalanche. Only Malness remains uninjured enough to continue. He attempts to snipe the Princess from an elevated position, but only injures her. In her pain, she regains her memory and is no longer possessed by the Martian. Before Malness can take another shot, another stray blast from Ghidorah buries the assassin under a second avalanche. With the heroes thus saved from the human menace, they gather at a safe distance to watch the battle between earth's monsters and Ghidorah. After now gaining a clear advantage over Ghidorah, the three monsters coordinate their attack; Godzilla grabs hold of Ghidorah's tails while Mothra (riding on Rodan's back) sprays the three-headed dragon with her silk while Rodan fires his Uranium Beam. Finally, Godzilla throws the alien beast off the cliff and the battered dragon flies off, back into outer space.
As the Shobijin return to Infant Island while Godzilla, Rodan, and Mothra head for Monster Island to form a coalition of kaiju known as the Earth Defenders, Selina, having retained the memories of her time with Shindo, bids farewell to her guardian as she meets her bodyguards at the airport to return home.
Differences from Original
- The original film was known as Ghidorah, The Three-Headed Monster. The title was changed here to reflect Godzilla's transition to a heroic role.
- A new sub-plot is added in which Godzilla contemplates his own morality and shifts alignment
- It is explained that the other Mothra Larva was killed by Varan; In the original, her death was never explained, and was open to interpretation
- Selina's visit to Japan is veiled in Cold War tension between the USA and USSR; there are, in fact, several references to Seligna being caught in the middle of growing tensions between China and the USSR added
- King Ghidorah is but one member of a vast species of space dragons known as the Ghidorah, and it is hinted that there are many more alien kaiju species