The film received a very limited theatrical release in the United States in early 1977 by Cinema Shares as Godzilla vs. The Bionic Monster. After roughly a week into its release, the film was reissued with the altered title of Godzilla vs. The Cosmic Monster.
Strange events are taking place in Okinawa. An Azumi priestess has a terrifying vision of a city being destroyed by a giant monster. A type of metal not found on earth is discovered in a cave by a spelunker, Masahiko Shimizu, who takes it to Professor Miyajima for examination. An excavation led by Masahiko's brother Keisuke accidentally uncovers a chamber filled with ancient artifacts and a mural bearing an ominous prophecy: "When a black mountain appears above the clouds, a huge monster will arise and try to destroy the world; but then, when the red moon sets and the sun rises in the west, two more shall appear to save humanity." Keisuke is joined by archaeologist Saeko Kaneshiro, who translates the prophecy and takes one of the artifacts, bearing the likeness of the legendary monster King Caesar, to study. Two men stalk them, one who speaks to them and claims to be a reporter interested in the story, the other of whom attempts to steal the statue from them but fails and flees.
Before long, the first sign appears in the form of a black cloud that looks like a mountain. Godzilla (or so it seems) emerges from Mount Fuji and begins a destructive rampage, despite the fact that he has become tolerant of humans within the last few years. Anguirus, usually Godzilla's ally, confronts him only to be mutilated and forced to retreat, but not before inflicting a wound that exposes something shiny and metallic beneath Godzilla's skin. Keisuke arrives shortly after to make sure that his brother and the professor are out of harm's way and discovers another sample of the strange metal. Godzilla's rampage continues, but another Godzilla arrives and the two begin to fight. Soon, the challenger is revealed to be the true Godzilla, while the other turns out to be Mechagodzilla, a massive robot armed with advanced weaponry. The real Godzilla is severely wounded but inflicts some damage on the machine; both monsters retreat hastily. Miyajima hypothesizes, based on MechaGodzilla's advanced technology and composition of unearthly metals, that the robot is an alien super weapon.
Keisuke and Saeko take the statue of King Caesar back to the temple by cruise ship, but are confronted by the thief once again. During the fight, the stranger's head is wounded and the skin on half of his face melts away to reveal an apelike visage. The intruder attempts to kill Keisuke and nearly succeeds, but a bullet from an unseen gunman kills him and propels him overboard. Keisuke and Saeko catch a brief glimpse of the "reporter" once again. Meanwhile, Godzilla arrives on Monster Island during a thunderstorm and is struck by lightning multiple times, seemingly reinvigorating him.
In the early hours of the morning, a lunar eclipse results in a red moon and a mirage creates the illusion of the sun rising in the west. The team realizes that the time has come to awaken King Caesar. They meet with the Azumi priestess and her grandfather, and place the statue on a platform in the temple, revealing the monster's resting place. However, just then, Kuronuma dispatches MechaGodzilla. The priestess sings a hymn that awakens King Caesar, and Godzilla appears shortly afterward. King Caesar and Godzilla fight together, but they are no match for MechaGodzilla's vast array of weapons. Eventually, Godzilla uses the electricity stored in his body from the lightning to create a magnetic field that ensnares the robot, then removes its head, shutting off its controls. While the mortified aliens are distracted, Nanbara and the others free themselves, kill their captors, and sabotage the base, fleeing as it burns and collapses on itself. With the enemy defeated, Godzilla heads out to sea and King Caesar returns to its resting place while the heroes rejoice.
Masaaki Daimon as Keisuke Shimizu
Kazuya Aoyama as Masahiko Shimizu
Akihiko Hirata as Professor Hideto Miyajima
Hiroshi Koizumi as Professor Wagura
Reiko Tajima as Saeko Kaneshiro
Hiromi Matsushita as Ikuko Miyajima
Goro Mutsumi as Kuronuma, Black Hole Alien Leader
Shin Kishida as Nanbara, Interpol Agent
Godzilla, The King of the Monsters and the titular character of the film who is also prophosised to defeat the monster MechaGodzilla.
Anguirus, a giant ankylosaurus creature who fights MechaGodzilla but is severely injured and retreats.
King Caesar, The Guardian Monster of Okinawa and a giant shisa-like deity who represents the Azumi Royal family and awakens to help Godzilla defeat MechaGodzilla, as he is also prophosised.
MechaGodzilla, The Magnificent Machine and the main antagonist of the film, MechaGodzilla is an alien, cybernetic double of Godzilla created by an alien race.
Giant Monsters Converge on Okinawa! Showdown in Zanpamisaki was the original concept for the 20th anniversary film for the Godzilla franchise. The story was created by Shinichi Sekisawa and Masami Fukushima, while the screenplay was developed by Hiroyasu Yamaura and Jun Fukuda and was submitted in 1973. The concept continued the trend of aliens using a monster to try and conquer Earth, and was also the second attempt to try and create an entry in the Godzilla series that took place in Okinawa after the scrapped Godzilla vs. Redmoon. Nami, best known as the princess who awoke King Caesar by singing to him. If she was going to play a similar role with Mothra in this production, or something else altogether, is unknown.
According to The Godzilla Fan News Letter by Richard H. Campbell, the film sold approximately 1,330,000 tickets in Japan - modest business, but an improvement of about 350,000 over the previous last 5 Godzilla films.
In 1977, Cinema Shares purchased the rights to Godzilla vs. Mechagodzilla and released the movie through Downtown Distribution under the title Godzilla vs. Bionic Monster. As they had done with Godzilla vs. Megalon the previous year, Cinema Shares simply utilized the Toho-produced English dub. In July 1977, Universal Studios filed a lawsuit threat against Cinema Shares, claiming that the title was too similar to their TV productions, The Six Million Dollar Man and its spin-off The Bionic Woman. Cinema Shares retitled the film Godzilla vs. Cosmic Monster.
A new title card. In the Japanese and international versions, Godzilla's name flashes several times while a mountain explodes in the background. As Masaru Sato's music plays, the full title is revealed. In the Cosmic Monster version, the screen turns bright red (covering up the original title) and the film title and copyright information appear. Widescreen versions of the title sequence feature the poster art to the right of the title, but this is not visible in the 16mm prints that have circulated since the early 1980s.
The opening credits have been deleted.
Also deleted is a scene in which Nanbara, the INTERPOL agent, strangles one of the aliens. The final shoot-out between Nanbara and three of the simian invaders is similarly edited.
At the end of the Japanese version, King Caesar returns to his resting place and Godzilla to the sea. In a short epilogue, the Azumi princess runs through her homeland celebrating with many of the characters. One of the King Caesar statues appear as the Japanese symbol for "end" appears. Cinema Shares cut this short epilogue, with the exception of the final shot of the statue. A red bar appears on the right side of the screen, with "THE END" overlaid on it.
In 2004, TriStar released the international version on DVD. The original Japanese audio was included as an extra audio track.
Godzilla vs. Mechagodzilla - Japanese title, Toho's official English title, and the UK and US home video title.
Godzilla vs. The Bionic Monster - Original American title.
Godzilla vs. The Cosmic Monster - Second American release title and UK theatrical release title.
The movie has become popular among fans in recent years for its exotic music, colorful special effects and entertaining monster fights. The film's robust themes and fairly complex plot stand out against a time when the Godzilla franchise was being fueled by increasingly lower production values.
Outside of the circle, however, public reception is luke-warm at best and the movie garners only 6 stars (out of a possible ten) at IMDB. However, it does retain an above-average score (60%) at Rotten Tomatoes.