One evening, young Mikko Mura receives a telephone call from an unknown man identifying himself as a messenger of Rodak, a conqueror from outer space. The caller tells Mikko that Rodak will take the boy, his mother Tomoko and his father Tom on an interesting journey at 6:00 AM the following day. The next morning, Mikko awakens and finds that his neighborhood has been transformed into a primitive jungle. A large dinosaur appears, and Mikko runs into the jungle to look for the unusual creature. The dinosaur sees him and begins to walk in his direction. Suddenly, Rodak’s saucer appears in the sky and destroys the creature with a special ray. Dropping from his ship, Rodak tells Mikko and Tom Mura— a reporter for United Press International— to print in the newspapers what they have just witnessed. Before Rodak flies off, Mikko takes a picture of him with his camera. With his house back in the old neighborhood again, Mikko has the photo developed. He then hears the loud roar of a jet engine, and looks outside to see a huge rocket land beside his house and immediately turn into a 50 foot tall golden robot. The giant introduces himself as “Goldar”, a friend to the people of Earth. Goldar asks Mikko for the picture. When Mikko refuses, the camera flies from his hands and into the giant palm of the Space Avenger! He tells Mikko that he must show the picture of Rodak to his creator, Mathusam, a scientist from outer space.
Goldar takes Mikko to his base, located deep in the heart of the active volcano Mt. Olympian. There Mikko meets Goldar’s wife Silvar, and Mathusam, the elderly, white-haired scientist. Goldar and Silvar are taken with Mikko and ask Mathusam to create a son for them in Mikko’s image. He grants their wish, creating “Gam”, a boy robot who can change to a rocket just like his parents. Mathusam also gives Mikko a supersonic whistle to call for help whenever he is in danger. One blast will summon Gam, two blasts will call Silvar and three blasts will bring Goldar the Space Avenger into action! As a show of force, Rodak sends his mechanical creature Molesaurus to Earth. Mikko returns to his parents’ home and learns his father Tom Mura has been assigned to cover the story. Tom boards a train, but suddenly the creature Molesaurus attacks from underground! The survivors of the trainwreck seek shelter. Mikko and his mother learn about the accident and wonder if Tom is still alive.
Tom Mura is able to escape from the train wreckage and begins to look for help. As strange earthquakes begin to take place all over, Rodak announces his plans to conquer the Earth and asks that the people surrender their planet peacefully. Mikko calls for help and Gam, hearing the whistle, flies to his aid. They discover that Rodak’s creature is a mole-like animal that can move under the earth. From the air, Gam and Mikko spot Tom Mura walking in a daze. They land to help him and suddenly Molesaurus comes out of the ground to attack them. Mikko takes out his whistle, calling three times for Goldar!
Molesaurus is found to be carrying an H-Bomb in its body, planted there by Rodak! After being told this by Mathusam, Goldar is forced to let the creature escape deep within the Earth’s crust. Gam is hurt during the encounter with the creature, and is taken back to the base for repair of his electronic system by Mathusam. Rodak appears again and demands that the people of Earth surrender or he will blow up the entire planet with an army of monsters like Molesaurus. He states that he will wait for a white flag to be raised atop the tallest tower in the city. Rodak later hovers over the tower in his spacecraft, and his anger is aroused when he does not see any flag of surrender. Mathusam comes up with a solution. He gives Goldar a powerful magnet to force Molesaurus to move toward the North Pole where the bomb can be exploded without harm (except to Molesaurus).
Defeated by Goldar, Rodak concentrates on examining the structure of Goldar and his component parts to find the Space Avenger’s weakness. Tom Mura and his family have decided that a vacation is in order. While flying in a jet airliner, the plane suddenly sways. But it is not turbulence…the plane’s instruments do not function because of some outside disturbance. A strange saucer is seen flying outside the plane, then leaves the area. Tom meets with another UPI reporter named Kita, and together they investigate the whereabouts of the flying saucer. The saucer is located and turns out to be a small glowing mechanism that appears to be breathing! The object is brought back to the lab as scientists try to discover its origin. Not having the right equipment for further tests, the object is shipped by truck to another facility. On the back of the truck, the object begins to grow. As it crushes the truck with its increasing mass, the object changes into a new creature of Rodak’s: Birdaurus (Birdora)!
Tom Mura meets Silvar for the first time, and learns that this family of giants from outer space is on Earth to help defeat Rodak, whom they have been following for quite some time. Gam and Mikko decide on their own that they will attack Rodak’s spaceship. They are captured and confined in a transparent cage. Rodak attempts to gain their confidence and tells them that on his ship, children only play all day long. Rodak shows them many children playing all kinds of games, apparently happy. Mikko is somewhat taken in, but Gam knows that Rodak is not telling the truth! Gam rebels, and Rodak places him on a platform for examination of his electronic parts. Birdaurus attacks an atomic power plant and begins to destroy it. Goldar arrives to stop the creature.
Goldar attacks Birdaurus at the atomic power plant, but is tricked by the creature and drained of his power. Birdaurus heads toward the power plant to destroy it completely and release radioactivity throughout the world. Tom Mura and Kita run to the plant and— with the help of scientists— attempt to pull out the safety pin of the furnace, thereby eliminating the danger of radioactivity if the plant is destroyed. Tom succeeds, and the furnace is shut down. Silvar appears and fires a volley of rays at the creature, which flies off. Silvar goes to Goldar, who is too weak to stand. She supplies him with enough electrical energy to return to Mt. Olympian. Tom and Kita return to their car. As they drive away from the power plant their car is drawn up into the air by Rodak’s spaceship. Unaware that his father has been captured, Mikko gets Lily, one of the children on Rodak’s ship, to help him release Gam. Gam turns into a rocket ship and all three return to Earth. Mikko and his mother are visited by Kita, who says that he escaped from Rodak. Kita says that it is important that Mikko arrange for him to see Goldar, but the boy thinks that there is something strange about the reporter. Kita is actually a Lugo Man (Ningen Modoki)— one of Rodak’s Human Duplicates— in disguise. He buys a box of flowers for Goldar and asks Gam to deliver them. However, inside the box is a time bomb!
Gam brings the box of flowers to Mt. Olympian. Mathusam senses something is wrong and orders Gam to throw the flowers out into the open where they explode harmlessly. Gam believes that Lily was responsible and is an agent of Rodak. Mikko disagrees. Birdaurus appears again, and Gam turns into a rocket to see what the monster is doing. Kita offers a charm to Lily as a gift for Mikko. Mathusam soon discovers that a signal is coming from the charm, and Silvar determines that it is transmitting to Rodak. Mikko accidentally sees Kita reporting in to Rodak and realizes that it is not really Kita, but one of the Lugo Men. Gam takes Kita to a deserted island, making him believe that this is Goldar’s base. Kita discovers the trick, and Birdaurus is called. Goldar, now fully recovered, comes to battle Birdaurus and is victorious. Tom Mura and the real Kita escape from Rodak’s saucer.
One night, a fireball is seen falling from the sky. Tom Mura and his assistant/photographer Liz learn that the shooting star has landed in the northwest. They drive to the location and discover a yellow saucer. Convinced that the ship belongs to Rodak, Tom goes for help while Liz stays to take some photos. A Lugo Man appears from inside the saucer and captures her. Tom returns with the police, only to see the saucer explode and find Liz walking in a trance. Mikko and his mother Tomoko visit the planetarium, where he and other children are learning about shooting stars. All of a sudden, Rodak’s image appears on the planetarium “sky”. He tells of his plans to conquer Earth, because it is the most beautiful planet in the universe. In the confusion to leave the planetarium, Mikko is separated from his mother. Tomoko is followed by a sedan and is captured by four Lugo Men! While Mikko is asleep, Tomoko enters his room and takes the whistle. She blows the whistle many times. Thinking it to be an emergency, Gam, Silvar, and Goldar all respond. Mikko is startled and rushes outside to see his mother confronted by all three robots. She is frightened until Mikko explains the use of the whistle. All agree that it was a mistake. The next day Mikko goes to his father’s office at United Press International and tells him that he left a tape recorder running in the house. As Mikko’s mother calls Rodak for instructions, every word is being recorded. Mikko and Tom come home and accuse Tomoko of being an imposter. Realizing that she has been trapped, she turns into a Lugo Man and disappears through a wall. Rodak informs the world that his latest monster Zandosis (Frenix) is draining all the sound waves from the air and that a silent world will soon be a dead world.
Tom and Mikko take the tape recorder to the authorities and play the recording of Tomoko contacting Rodak. The inspector, who unbeknownst to Mikko and his father is in reality a Lugo Man, uses his powers to add a commercial at the end of the conversation, making the entire tape seem like a radio program. Goldar and Silvar spot a creature in the ocean that has been destroying ships at sea. It is noted that when the monster is on the surface, there are no sound waves in the air. Mikko and Tom follow Liz, whose identity has been taken by a Lugo Man. They tail her by car to a deserted jungle area where she meets another hooded Lugo Man in a silver uniform. They overhear the man tell Liz that soon an army of Lugo Men will arrive on Earth to take over the identity of humans in the first step to conquering Earth. The Lugo Men begin to arrive in saucers, and demonstrate their ability to walk on water. The aliens arrive at Mikko’s house and find Gam there. They believe he is Mikko, but he uses his electronic rays to fight them off. Mikko and his father follow the Lugo Men and Liz to a local hospital. They see Tomoko being wheeled out… all the nurses at the hospital have been taken over by Lugo Men. The sea creature Zandosis shoots down U.S. Navy patrol aircraft.
The Lugo Men put all of their victims, humans without identities, in a truck for transportation to another location. Mikko and his father watch the Lugo Men, but are helpless to do anything. Tom Mura tells Mikko to continue observing them from their hiding place while he goes to the police for help. The police do not believe his story since their identities have been taken over by Lugo Men, and Tom is put in a jail cell. The aliens are about to steal Mura’s identity when Silvar blasts in to rescue him. Flying over the ocean shipping lanes, Goldar spots Zandosis and begins his attack on the creature!
Goldar attacks Zandosis, but the creature is too strong and escapes into the ocean depths. Goldar returns to Mt. Olympian and tells Mathusam that the creature has escaped and that a better means of fighting the creature must be devised. Mura attempts to tell his bosses at UPI that Liz is not Liz, but no one will believe his story. Gam and Mikko follow Lugo Men as they leave the hospital. Mikko worries about his mother, one of the captives aboard the Lugo Men’s truck. The villains arrive at a deserted area where they plan to dispose of all their victims. Mikko calls Goldar to help and the Space Avengers arrives to destroy the Lugo Men. All the victims are safely revived. Meanwhile, Zandosis causes hurricanes out at sea. Mathusam creates a new weapon for Goldar to use against the monster: an instrument to absorb all sound waves. The weapon works, and Zandosis is destroyed and sent to the bottom of the sea.
An observatory in Australia reports a mysterious S.O.S. signal coming from a planet in outer space. The planet is called Kuwal (Pal), and it has been attacked by the heat creature Taron (Aron), sent there by Rodak! The King of Kuwal tells his daughter Lita (Lihza) that she must escape to Earth in a space-boat and tell the people of Earth what has happened. Tearfully, Lita leaves her father and escapes the doomed planet. Gam finds Lita and her space-boat crashed in the desert and takes the girl to Mikko and his father, Tom Mura. Rodak’s assistants report that only one survivor of Kuwal has made it to Earth, the daughter of the King, and that she may have some important documents. Rodak’s robot men go after Mikko, Gam, Tom and Lita, forcing their car off the road and over the side of a mountain, but the heroes escape without injury. Meanwhile, the temperature on Earth seems to be rising; even the water is becoming hot. Volcanoes erupt and lakes bubble with steam. Gam takes Mikko for a closer look at the erupting volcano, and there they discover Taron! Goldar and Silvar are called. Goldar attempts to defeat Taron, but the creature retreats back into the mouth of the volcano.
Rodak’s agents spread the rumor that Goldar is responsible for the disasters and is actually an assistant to Rodak! Mikko calls the Space Avenger to have him refute the rumors in person, not knowing that Rodak wants to get Goldar out in the open so he can be shot down by the Army’s guided missiles. Tom Mura tries to destroy the evil Lugo Man who is posing as the police inspector, but is found out. Mikko sends Gam to defeat the Lugo Men. Meanwhile, Lita is captured by other Lugo Men and taken to a secret house, where Rodak suddenly appears and questions Lita about a locket given to her by her father. Rodak again shows her the destructive power of the heat creature Taron. Mikko learns where Lita is being held and signals Goldar to free her.
Goldar confronts Rodak. The two enemies shoot electronic rays at each other, but Goldar’s attack is too strong and Rodak retreats. Rodak tells Taron to start destroying the area. Goldar flies to confront the heat creature. Goldar tells Gam that an island base has been set up to train Lugo Men and imprison the many people who were captured to give Lugo Men identities. Goldar suggests that Silvar also go along to free the captives. Silvar, Gam, and Mikko go by boat to the edge of the island, and there, Silvar places a powerful explosive in a watch which is strapped to her wrist. She dons scuba-gear and swims toward the island. Her foot accidentally strikes an underwater signal device, setting off an alarm on the Lugo Men’s control board. The Lugo Men, armed with spear guns, dive into the water to search for the intruder. Silvar escapes detection and goes ashore onto the island. She places her wristwatch containing the explosive device and the island is blown up. Goldar fights Taron, but the tide of battle begins to turn against the Space Avenger. Mathusam causes a solar eclipse which causes Taron to lose energy. Rodak declares that he will not allow Goldar to win. He will create tremendous heat so that the North and South Poles will melt, causing tidal waves all over the Earth!
United Press International receives information from their New York office that tidal waves are destroying harbors in Norway, Sweden, Denmark, Alaska, the Soviet Union and Australia. Mathusam creates a rainstorm to cool down the temperature, however the rain is heated and is no help. Lita remembers the watch her father gave her and feels that it is important in solving the world’s problem, but the Lugo Men are also after it and shoot the girl with an invisible ray. Goldar decides to give Rodak a taste of his own medicine. Flying into the heart of an active volcano, the Space Avenger absorbs all of its heat. Goldar head directly for Rodak’s saucer and releases his built-up heat directly into the ship. Rodak calls for the cold of the North Pole, which destroys the heat of Taron. The temperatures return to normal and Rodak is defeated again!
A strange, fatal disease spreads across Earth. All who come in contact with it turn blue. Then cause of the disease is Rodak’s latest creature, Ranautis (Gareon), a monster that has the power to turn red blood cells into blue. One of Mikko’s friends becomes ill and is taken to the hospital. Tom Mura and his assistant Liz go to the hospital to talk to the doctor about the disease. Checking medical records, the doctor discovers that all patients with the disease have been transferred to Moz Hospital. Doctor Moz, who runs the hospital, is working for Rodak. He kidnaps the patients and replaces them with replicas under his control. Mikko sees Doctor Moz at work and tells his friend that his sister has been replaced by an imitation human.
Tom Mura discovers Doctor Moz’s true plans, and the authorities make a raid on the hospital. Doctor Moz escapes by a rocket ship that was hidden beneath the hospital roof. The creature Ranautis attacks a car containing Tom, Liz, Mikko and Gam, but Gam forces it to withdraw. The monster attacks again and Goldar is called to help. Goldar’s missiles strike Ranautis, only to melt away. Trying another weapon, a colored liquid, the Space Avenger causes the beast to retreat. Two workers come across a group of life-size dolls, only to discover that they have heartbeats! Frightened, they call the police. It is discovered that Ranautis absorbs blue flowers and changes the pigment of the flowers into a ray which penetrates the human body, causing all red blood cells to turn blue. Mathusam tells Goldar that only the seeds of the rare Balango plant can cure the disease. Mikko, Gam and Tom Mura head to a deserted island to locate the Balango seeds.
Mikko and Tom Mura hire a plane to take them to Balango Island, but the crew turn out to be Lugo Men. Mikko is given a sleeping pill by the stewardess, and then the pilots tell Tom that they work for Rodak. The Lugo Men disappear, leaving no one at the controls of the plane! Tom remembers Mikko’s whistle and blows it one time. Gam flies to their aid, and talks Mura in for a landing, guiding him in rocket form. Arriving on the island, the Muras and Gam meet Mary, the daughter of the scientist they were supposed to rendezvous with. Mary tells them her father has died. A guide leads them in search of the Balango seeds. The Lugo Men blow up a bridge, but Gam turns into a rocket and carries the heroes across. Going by foot into the jungle, they are met by Goldar, who tells Tom Mura that he must return to the city. Goldar leaves with Tom while Miko, Gam, Mary, and the guide continue their quest. They find the seeds in a cave which is guarded by Rodak’s monster, Drox!
While waiting for Drox to leave the cave entrance, Gam and Mikko get into a children’s argument about whether it is better to be a human or a robot. Gam feels insulted and flies off, leaving Mikko, Mary and the guide alone on the island. Mathusam decides to show Gam what it feels like to be human. Gam suddenly finds himself stripped of his rocket powers and becomes a real boy. He also learns that he has developed human fear. Mathusam explains to him that humans are different than rocket people. Gam, having learned his lesson, returns to being a rocket boy. Following the guide’s instructions, Mary begins playing her flute. The creature Drox begins to dance, and like the pied piper, Mary leads him away from the cave. As the monster dances away, Mikko goes toward the cave to retrieve the Balango seeds. Rodak sends Ranautis to block the entrance. Mikko calls Goldar for help, and suddenly Goldar finds himself caught between the two monsters! Goldar turns the two creatures against each other and they are soon destroyed. Mikko and Gam become friends again. The seeds are collected and delivered to scientists to help cure the blue disease.
Rodak sends three black liquid blobs that can impersonate humans to steal a secret formula. They head to the Research Center, where a conference is taking place with world scientists and a member of the United Nations. Changing from men to liquid blobs, the aliens get by the conference guards and steal a formula that eats vegetation, the substance which Lugo Men are made of. Tom Mura is assigned to follow up on the scientific conference. The Lugo Men overhear a scientist telling Tom that the formula Rodak stole was not real, but only a decoy. Rodak sends his latest creation Noronda (Stopgon) to Earth… a giant creature made of metal, which can paralyze any type of machinery. Gam and Mikko fly to the last reported location of Noronda and confront the creature. Gam flies around and around the monster’s head. Getting dizzy, Noronda falls backwards and shatters. But, to Gam and Mikko’s surprise, the creature’s metal parts reform. Noronda lives again!
Mikko calls Goldar to fight Noronda. Goldar shoots a missile at the creature, breaking it into small pieces. However, the monster just reassembles itself. Mathusam tells Goldar that he knows how Noronda breaks up into small pieces, and explains how Goldar can destroy the monster. Disguised Lugo Men, once again trying to steal the formula, kidnap the scientist Dr. Kura at the airport. Tom Mura sees the car pull away and gives chase. A hand grenade is thrown at Mura’s car, and he is injured. The Lugo Men take Dr. Kura to a secret hideout for questioning. At the hospital, Tom tells Mikko and Gam that they must find Dr. Kura because he is carrying the formula that can destroy the Lugo Men. A Lugo Man breaks into the hospital and captures Tom Mura, taking him to the same hideout as Dr. Kura. They force the doctor to give them the formula. Gam and Mikko rescue Mura and Kura and head for the launching pad where the formula can be loaded onto a rocket and shot skyward, showering down to destroy all the Lugo Men. But it is discovered that the doctor is actually a Lugo Man and the formula is a substitute which will kill all of mankind, and not the Lugo Men!
Goldar chases after the missile, but Noronda stops the Space Avenger with its holding-ray. Gam flies to help his father and is able to break the creature into pieces. Goldar catches up to the rocket and destroys it. In the meantime, the Lugo Men question the real Dr. Kura. He refuses to tell them where he is hiding the formula. The bacteria are actually hidden in Kura’s shoe, in a secret compartment he himself is not even aware of. Rodak orders the Research Center destroyed, and the Lugo Men attack. Gam uses radar to find the doctor and tries to rescue him while Mikko calls Goldar for help.
Arriving on the scene, Goldar finds the boys trapped in Noronda’s giant hand. He forces the monster to drop Mikko and Gam, and fights the creature as Rodak infuses it with more power from his spaceship. Transportation in the city stops as Noronda freezes all mechanical parts. Meanwhile, Rodak causes all laws of nature to act in reverse… rivers run backwards, the Earth begins to split into sections and plate glass begins to shatter on its own. Rodak’s new Titalia bacteria spread, covering its victims with a brown mold. One of the scientists suggests that a certain chemical will counteract the bacteria. Gam is called to disperse the chemical into the air. An x-ray photo is taken of Noronda’s heart. Mathusam tells Goldar that the heart of the creature is located just below the rib cage. When Noronda breaks up, Goldar must catch and destroy the heart, making it impossible for Noronda to reform.
In celebration of Christmas, Rodak launches a new wave of attacks. He sends his creation Vacuma (Dakoda) to Earth as a holiday gift. The creature hovers over the airport like a flying octopus, sucking planes into its long, writhing tentacles and crushing them. Another of Rodak’s “presents” are the Dwarf Robots (Micro Ningen), 6 inch high men that invade a person’s body and assume control of their thought processes. The robots begin to work immediately, dissolving into many people’s bodies and taking over their minds at the direction of Rodak’s chief henchman Sultan (Sarutan), who is assigned to oversee operations. Mikko buys a Christmas present for Gam. When Gam opens the packaging, the toy inside issues forth a spray that turns the boy robot into a concrete statue. Men under the control of Dwarf Robots appear and spirit Gam away. Toms Mura chases them in his car, only to be sucked up into the tentacles of Vacuma. Mikko blows his whistle three times, calling for the Space Avenger!
Vacuma grabs the incapacitated Gam with its powerful suction tentacles. Mathusam, however, tells the other heroes that this is actually a trap to lure them to Gam’s aid. The army sends its jets against Vacuma, but all are crushed. Mikko goes with Kita to look at the store where he bought Gam’s Christmas present. The pair tails the owner of the store to a house on a hill. They enter the house and find Gam frozen in a block of ice. As they approach Gam, iron bars drop around them, capturing Mikko and Kita as well. Mikko uses a heat gun to melt the ice, and Gam is returned to normal. A new creature— Gor (Black Giant) the faceless giant— confronts Goldar!
Mikko and Kita are still trapped in a closed room that is beginning to reach freezing level. The room is also soundproof, so Mikko’s whistle is useless. Gam, having escaped, reports what has happened to United Press International and then returns to help Mikko and Kita. As Silvar causes a distraction in the sky, Goldar moves underground toward the house. Rodak sends Vacuma to fight Silvar, but she avoids him. Mikko and Kita escape. The angry Rodak tells Sultan that he must executed for failing his mission. But before this can be done, Sultan escapes and heads toward Earth, landing at the Mura house. Tracking Sultan’s flight, Goldar and Gam arrive moments later. Sultan pledges allegiance to Earth and promises to fight against Rodak! Goldar agrees to trust Sultan. Rodak is furious with the escape of Mikko and Kita and with Sultan’s defection. He turns Gor loose on the airport. As Goldar heads to his confrontation with Gor, Rodak releases his army of Dwarf Robots to kill Sultan.
Rodak tells Goldar that Gor’s body contains an army of 6-inch tall robots which will be released if Gor is destroyed. The villain next orders Gor and Vacuma to destroy the military complex where Sultan is being kept. Sultan informs the authorities that only freezing cold can safely destroy Gor. Mathusam equips Gam with a freezing chemical. As Goldar attacks Gor, Gam throws the freezing chemical on the monster, defeating him once and for all. Rodak orders an all-out attack to find and kill Sultan before he can give away any more of Rodak’s secrets. Because Sultan came from a highly magnetic planet, Rodak is able to locate him with a powerful compass. He finds Sultan hiding in a hotel, Rodak shrinks Vacuma, enabling the monster to get inside the building and murder Sultan. Using Mathusam’s freezing compound, Goldar destroys Vacuma.
Rodak goes to New York and attacks the Statue of Liberty. Tom Mura, on assignment in in the city, calls Mikko and has him send Goldar to stop Rodak. Goldar and Gam arrive in New York and drive Rodak back into outer space. Mathusam is suspicious that Rodak went away without a fight. A hotel reports that ten of its guests have mysteriously disappeared. Kita is sent to cover the story. One of the caretakers tells Kita that people seem to disappear after going swimming. Kita asks if there is anything special in the water and is told that that the only additive is sulfur for health purposes. The caretaker even says that the water is drinkable. He demonstrates by drinking some of himself, but suddenly goes crazy and runs off. Kita decides to have the water analyzed. He is attacked by one of Rodak’s men, but is saved by Goldar. It is discovered that the water contains “Zana”(Zamaz), a chemical from outer space that acts as a radio transmitter. Just then, Mura calls from New York asking for Goldar to come back to Manhattan as Rodak is attacking again.
Goldar is assigned to New York to help against an attack from Rodak. Rodak sends his newest creature Gorda (Teravarden) to spread the Zana chemical into all the Earth’s water supplies, causing everyone who drinks it to come under Rodak’s control. The monster’s underground movements also cause volcanoes to erupt. Rodak orders his men to have as many people as possible drink Zana so that he can have an army of spies. Many drink the water and become Rodak’s willing slaves. Rodak orders all the missing guests to return to their hotels and await further orders. Gam, Mikko and Kita go to the hotel to investigate and come face to face with Gorda. Kita is captured by Rodak’s men. Rodak orders Gorda to create more volcanic eruptions. Goldar returns from America and is told by Mathusam that Gorda is responsible for the Zana and must be destroyed.
Goldar injures Gorda, but the monster escapes into a volcano. Goldar returns to Mount Olympian, where Mathusam begins to work on a new weapon to use against the monster. Kita is the prisoner of a doctor who has taken Zana. He is kept in a room, which gets hotter and hotter in order to force Kita to drink the Zana-contaminated water. Gam uses his sensitive, electronic headpiece to discover Kita’s whereabouts. He and Mikko enter the doctor’s lab by pretending that they want to take Zana. However, Gam’s headpiece causes anyone under the influence of Zana to become dizzy and they are found out. Locating Kita’s cell, Gam crashes through the wall and all three escape. Mathusam finally develops a special ray gun which can destroy Zana. Goldar successfully uses the gun against Gorda, and then instructs Gam to use it on all the people who took Zana. As Gam shoots the ray at them, they all return to normal, with no recollection of what they had been doing. Zana is no more and Goldar now seeks to destroy Gorda who hides in the depths of hot volcanoes where Goldar cannot follow!
Goldar battles Gorda near a volcano, but the rising heat becomes too intense for the Space Avenger. Mathusam sends Silvar and Gam to Goldar’s aid. Gorda returns to its volcanic lair, where Rodak orders it to stay hidden. Gam manages to get a small piece of Gorda’s skin for Mathusam to analyze. Mathusam discovers that the creature is from the planet Zephyr. The planet is dissolving fast and once Zephyr disappears completely, so will Gorda. Goldar flies Mathusam to his planet, where he gets his leader to agree to speed up the destruction of planet Zephyr. Rodak decides to cover the Earth with a heavy fog. As the army attacks Gorda, Mathusam creates a time ring which Goldar throws around the head of the creature. This causes Gorda to disappear at the exact same time as Zephyr and the Earth is safe again…for now.
Rodak’s every move is monitored by powerful radar systems at the Space Center which are zeroing in on Rodak’s spacecraft for a missile attack. The impact of the explosions is felt at the center, leading the Earth forces to believe they are victorious over the space villain. But Rodak laughs at the missile attack, and orders a fireball horde of alien insects to attack the Space Center. Four army jets discover the insects streaking toward Earth, but are destroyed before the pilots can report what they have seen. Mikko and his friends are playing baseball when the swarm of insects lands on the backstop and begins eating the metal. The bugs next attack the Space Center as well as various buildings throughout the area. Gam turns into a rocket and he and Mikko attack the bugs. Gam’s ray seems to stop some of the bugs, while the others fly away. Gam and Mikko follow the fleeing swarm only to come face to face with the giant beetle, Nardo (Pidora). The beetle flaps its wings, creating a strong wind while throwing out bolts of fire rays. Mikko calls for the Space Avenger!
Goldar arrives and attacks Nardo! As the two titans fight, Rodak’s ship appears overhead and Rodak announces that Nardo will keep Goldar busy while the insects do their job. Nardo eventually retreats and the boys inform the authorities what has happened. The radar units scan for the bugs, with no luck. American scientist Dr. Reed is coming from New York with a plan to stop the bugs by using shock waves. Using a hidden transmitter, Rodak learns of the arrival of the doctor and his plan. Tom Mura goes to the pier to greet Dr. Reed who is arriving by boat. Rodak sends Nardo to destroy the ship. However, Dr. Reed is actually travelling by submarine, ruining Rodak’s plan. Silvar is sent by Mathusam to find out where the insects are and what sustains them on Earth. She discovers a plant (Nesugiras) that gives the insects their energy. Moving closer, the plants come alive, catching her. Goldar rescues Silvar, but finds out that his ray does not damage the plants.
Goldar and Silvar report back to Mathusam. He tells them that the space plants must be uprooted, but does not know how best to do that until he studies them more. Meanwhile, Gam meets with Tom Mura, Mikko and the authorities at a lighthouse to await the arrival of Dr. Reed. As the scientist and the Commander come ashore, Rodak attacks! Dr. Reed and the Commander try to escape, but before they can get away, Nardo sucks their car up into the air. Rodak’s bugs attack everything in sight. Mathusam tells Goldar that he must fight Rodak and rescue Dr. Reed and the Commander. Rodak confronts Goldar, but Nardo flies overhead and sends out streams of fire that encircle Rodak’s captives. Goldar can not come any closer due to his sensitivity to heat. Rodak appears at Mount Olympian and tells Mathusam, Silvar, and Gam that Goldar is trapped and soon the world will be his!
Goldar abandons his attack on Nardo and saves Dr. Reed and the commander, bringing them back to the United Press International building. Mikko informs Goldar that Gam is not responding to his whistle. Goldar immediately leaves for Mount Olympian and confronts Rodak just as he is about to destroy the base. Not wishing to fight Goldar, Rodak disappears. Rodak orders the bugs to launch an assault on oil tanks that will fill the air with dangerous vapors. People are instructed not to strike a match or cook as the combustible gases in the air can cause explosions. A cold spell is forecast by the weather bureau. Mikko calls Goldar for help, but he cannot respond for fear that this rocket jets may cause an explosion. Rodak issues a demand for mankind to surrender the Earth or Nardo will ignite the atmosphere. Goldar places himself in jeopardy and decides to create a jet stream that will clear the atmosphere of the gas vapors. Accomplishing his mission, he attacks Nardo and defeats the creature!
After observing an H-Bomb test, Rodak makes plans to steal one of the bombs and have the countries of the world blame each other for the crime. A jet bomber carrying H-Bombs is hijacked. To Rodak’s surprise he discovers that his men were not responsible. Central Intelligence discovers that it was Horonda, leader of the underground organization The Orange Order, who stole the plane. Gam and Mikko set out recover the lost plane, but they are forced to retreat when the jet fires on them and Gam’s rudder is damaged. Tom Mura tells his newspaper chief Mizuno that he knows what Horonda looks like, but that he has many disguises. Mura knows that Horonda will attempt to get into the city by any means. Tom and Mikko go to the railroad terminal, where they notice an unusual woman, which Tom recognizes as Horonda in disguise! They follow Horonda to his hideout and overhear the terrorist’s plan to use the bomb to force all the countries of the world to turn over their armies to him. As they are about to be discovered, an assistant of Rodak’s appears. They follow him outside, only to be confronted by Rodak and his Lugo Men. Rodak meets with Horonda and forces him into an agreement to work together. World leaders hold a conference to sign a treaty banning all nuclear weapons. Suddenly, Rodak’s creature Claw (Sangiras) is sent to Earth to break up the meeting. Mikko calls Goldar for help!
Goldar arrives and is attacked by Claw. Rodak is furious that his creature has turned its attention away from the meeting of world leaders. Goldar stops Claw and the monster disappears. Goldar tells Mathusam that Claw is able to send out a red stream of nerve gas from its tail. While Mathusam works on a plan to combat the monster’s poison, he instructs Goldar that the three H-bombs Horonda stole must be found. The Commander decides to attack Horonda’s hideout. His forces close in on the house, but find it empty. Claw flies over a military exercise and incapacitates the troops with nerve gas. Mikko and Gam fly in to investigat. They follow the trail of red gas to Horonda’s new hideout, a. warehouse where it is believed that the bombs are hidden. The Commander and his forces try to get into the house, only to be met by Horonda’s men. A volunteer enters the warehouse and defuses one bomb, but there are still two missing.
Rodak calls the monster Dilas (Grania) to Earth to destroy Goldar. Claw is also reactivated by Rodak, and now the Space Avenger faces two monsters! As Goldar battles Dilas, the creature disappears. Horonda and his men have Mikko, Gam and the Commander pinned down. Goldar comes to Miko’s assistance, but not before Claw infects Mikko with nerve gas. Horonda escapes and meets with Rodak. The two villains decide to detonate the H-Bombs. They kidnap the daughter of an army H-bomb expert, Yazowa, to force him to set the timing device. But, instead of freeing Yazowa and his daughter, Horonda and Rodak tie them to the bomb. Mikko recovers and calls for Goldar when Dilas attacks. Unaware that Yazowa has cleverly installed a tiny safety mechanism in the H-Bomb, Rodak begins the countdown to the big explosion. There is only a small, sparkling blast in which Yazowa is hurt.
Rodak attacks a false image of Goldar, an illusion caused by a special projector. With Rodak distracted, Goldar drops the second H-Bomb into the Atlantic Ocean. There is still one more bomb to be located. Rodak plans to explode the third H-Bomb over New York. Rodak also works with Horonda on a new plan to spread poison gas from a factory smokestack. The factory is attacked by troops wearing gas masks. Horonda counterattacks and Goldar is called to help. Horonda is killed in the battle, and the poison gas is shut off. The last H-Bomb is attached to the back of Dilas. As Goldar confronts the creature the bomb is released into the air towards New York. Goldar defeats Dilas and then uses all of his incredible speed to overtake the bomb. Attaching himself to the H-Bomb, he flies it into space and sends it hurtling towards Rodak’s ship! Rodak sees the bomb approaching and orders it detonated in mid-air. Rodak is beaten again.
Adults and children are enjoying themselves on the various rides at a local carnival, when all of a sudden Rodak’s newest creature Ghana (Balzas) appears! Ghana wrecks the carnival, disappears, and then reappears in another spot on a road, only to disappear again. Mikko and Gam arrive on the scene and spot Ghana’s footprints. They notice the footprints head in one direction and then another. Mathusam tells Goldar that Ghana is composed of vegetation and has the power to disguise itself as anything organic such as blade of grass or a tree. The latest report places Ghana at the zoo. Mikko, Gam, Kita, the Commander, and his troops, head to the location. They hear loud footsteps coming from some of the cages, but find nothing. Mikko and Gam decide to go back to the carnival in search of clues. The boys search high and low. Suddenly, Gam finds a small flower, all by itself, in the sand. Remembering what he was told about Ghana’s abilities, Gam fires a ray at the flower and it becomes the monster! A call goes out for the Space Avenger! However, as Goldar arrives, Ghana disappears again without a trace.
Ghana reappears at the entertainment park. Goldar attacks with his ray and Ghana goes down. Rodak appears overhead and tells Goldar that the smoke coming from Ghana is a poisonous mist, which will destroy all of mankind unless the people of Earth surrender within 24 hours. Mathusam tells the space family that they must keep Ghana in sight at all times until he can devise a weapon for its destruction. When the 24 hours are up, Rodak gives the Earth one more hour before he releases the poisoned pollen. Ghana disappears, but under the Commander’s orders, the troops use tear gas to force the monster back into the open. Mikko calls for Goldar, who decides to keep the creature busy until Mathusam can complete his weapon. Soon, Mathusam completes a special gun that is designed to destroy plant cells. Gam takes the gun to Goldar. Using the new weapon, Goldar fires it at Ghana, freezing the monster and then hitting it with his own rays. Ghana is defeated and the pollen is rendered harmless.
Rodak heads out into deep space to regroup his forces. His flight is tracked on radar via satellite. Rodak leaves his assistant Tocka on Earth to plant a bomb in an art museum. Mathusam senses something wrong at the art museum and tells Mikko, Gam, Tom Mura, and Kita to investigate. They drive to the museum and discover an unusual statue, which suddenly emits a strange smoke. Everyone flees the building just before the museum is destroyed. A new beast, Magno (Jigira), appears and traps Gam against one of its magnetic horns. Mikko calls for Goldar, but Magno drops Gam and retreats. Tocka records Mikko’s whistle and uses hundreds of recordings to lead Goldar on a wild goose chase. The confused Space Avenger reports back to Mathusam, who informs him that he is not listening carefully enough as only Mikko’s whistle emits a natural sound. Magno attacks an electrical power plant and Goldar is called for help!
The Commander finds out that Goldar is not available to help. He orders his troops to attack Magno, but their guns and tanks are useless against the creature’s magnetic powers. In the depths of outer space, Rodak decides to relaunch his assault on Earth with additional monsters. Goldar pursues Rodak, carrying a bomb to launch at the evil alien. Rodak sees Goldar approaching and orders meteorites to be aimed at the Space Avenger, but Goldar is able to survive the attack. While spying on the military complex Tocka is captured by Mikko and Gam. Tocka destroys himself. Believing Rodak is dead, space control celebrates. Silvar reports that Rodak has not been destroyed, however, his planet has been turned into a gigantic meteor and is heading towards Earth! Mathusam tells Goldar that he must destroy Magno, as the monster’s magnetic powers re pulling the meteor towards Earth. Once the beast is destroyed, the meteor will change course away from Earth. The only way for Goldar to defeat Magno is to shoot four million volts straight into the creature’s brain, but this may weaken Goldar to the point where he may not recover. Goldar decides to take the risk in order to save the Earth. Magno is defeated, and the meteor immediately changes direction and heads off into space.
A new monster appears on Earth! Gonda (Umibozu), a creature that can change from normal size to giant instantaneously, attacks young people and destroys cars and trucks. However, this creature is not Rodak’s! Rodak orders his men to find out what Gonda is and who sent him. Both Rodak and Mathusam feel some kind of unusual energy from the Nastric galaxy. United Press International sends Kita to investigate Gonda. An elderly man named Kazuki (Harada) talks about his grandson, Taro, who was killed by a truck. Kazuki later tells his wife that he is happy that Gonda is destroying motor vehicles. Kita, Gam, and Mikko see Gonda smashing a car. Gam attacks the creature, but nothing happens. Goldar is called, but Gonda retreats. Goldar says that it is true that the monster is not one of Rodak’s, and that it has the heart and mind of a human.
Kita develops his photograph of Gonda, but the picture shows nothing. Rodak finds Gonda and follows him to the Kazuki’s home. Gonda disappears as Kazuki awakens from a trance. The old man admits to Rodak that he is Gonda and is avenging his grandson’s death. Rodak offers him a pact: in return for Gonda’s help, Kazuki can have all the revenge he wants on mankind. Since Kazuki is unconscious each time Gonda is activated, Rodak shows the grandfather for the first time an image of his monster. Meanwhile, Kita, Gam and Mikko arrive at the house and overhear Rodak’s offer. They are discovered and chased by Rodak, Kazuki, and Gonda. Mikko blows his whistle three times. Goldar arrives and battles Gonda, destroying him. Kazucki returns to his normal self, ashamed of his actions. Rodak again retreats back into outer space.
Rodak plans his next move, creating Lodi (Kanix), a miniature creature. To make it grow into a giant monster, Rodak must learn the secret of electromagnetic waves, but only Kazuki knows the answer. Rodak kidnaps Kazuki and takes him to his spaceship. He tortures the old man by showing him illusions of his dead grandson Taro. He tells Kazuki that he will allow him to keep the illusion as long as he gives Rodak information on how he created Gonda. Kazuki initially refuses, but the images of his grandson are too much and he tells all. Lodi is then sent into space, returning to Earth as a giant monster. Kazuki is returned to Earth, double-crossed by Rodak! Lodi attacks Shinjuku and the army retaliates against the beast. The monster disappears, reappearing in a new location. United Press International finds the monster, and Goldar is called. Goldar fights Lodi, only to let him go when he finds out that if he destroys Lodi, Kazuki will also die.
Rodak proclaims that his new monster Lodi will attack the schools of the world if the Earth is not surrendered to him. Lodi appears in several locations but the army troops, using bazookas, cannot harm him. Mathusam calls a meeting of the Space Giants to discuss the situation. He says that the only way to defeat Lodi is to cut the monster off from the electromagnetic rays that give him his power, and shrink Lodi back to its original size. Kazuki is visited in the hospital by a citizens committee, who blame him for the antics of Lodi. The old man is distressed that there is a link between him and Lodi; they both feel the same things so any harm to the monster also affects Kazuki. Kazuki returns home, only to find Rodak waiting there for him. Kazuki angrily tells Rodak that they are no longer partners. Rodak’s henchmen take Kazuki outside where they are confronted by Goldar. Rodak escapes just as Lodi appears. Goldar battles the monster. Kazuki decides to destroy Lodi, even if it means his own death. He touches the monster’s foot, sending electric waves into him. Goldar destroys Lodi and Kazuki is killed as well.
An Earth ship is launched to study the planet Venus. Rodak observes the rocket and is furious that the Earth people are invading his territory. He decides to attack the spaceship and render it inoperable. Goldar is called for help and goes after the rocket. Goldar attaches himself, in rocket form, to the disabled ship and starts to fly it home. Rodak causes Goldar to lose control and he lets go of the rocket, sending it crashing to Earth. Two hunters find the ship and notice part of the hull is a golden color. Believing it to be real gold, the hunters think they are rich. Mikko and Gam search for the lost ship and landing beside it. Suddenly, there is a large explosion, and through the smoke emerges the monster Rada (Kindora)! Gam’s powers are useless against the creature, so Mikko calls for Goldar. As Goldar attacks, they notice that Rada has the power to rejuvenate lost limbs. After a short fight, Rada retreats. The two hunters are rushed to the hospital, but by the time they arrive, all that is left are their skeletons. The doctors say that the cause is a living orange liquid which was brought to Earth on the rocket ship. Mathusam tells Goldar that Rada must be destroyed before it can spread more of the orange liquid.
Goldar battles Rada again, but the monster reproduces every limb that Goldar destroys. Goldar attempts to incinerate the beast with his jet rockets, but Rada only disappears. Goldar reports to Mathusam, who tells him that Rada is composed of Space Bacteria that enables it to disappear when in danger. Gam and Mikko search the area looking for Rada and run into a cloud of orange color. Figuring that it is the Space Bacteria, they quickly leave the area. At the hospital, Tom Mura interviews all the victims that have come into contact with the orange liquid. One patient mentions that he had seen the color green. Perhaps this could be a form of cure? Tom and Mikko leave to see if they can locate the green liquid that could be the answer to their problems. Along the way, they encounter two strangers attempting to flee the area. They overpower Mikko and Tom and steal their car. Tom and Mikko search for a place to hide from the approaching orange mist and find an empty house. The orange mist comes closer, only to be turned away by a green plant which surrounds the house. This green plant is an antibiotic which followed the orange liquid from space to the Earth. Rodak issues orders for Rada to continue spreading the disease. Goldar and Gam attack with the green spray and Rada is destroyed.
Rodak’s men look at a memory machine showing all the creatures that the mighty Goldar has beaten. Rodak decides that he must now bring to Earth the strongest monster of them all, Kono (Goa Gongon), for the final attempt at defeating Goldar. Mathusam has been gone for three days and the Space family is worried. Rodak causes an eclipse, plunging the Earth into darkness. Rodak sends a parrot to spy on the Mura family. The bird flies in Mikko’s open window and his parents Tom and Tomoko decide he can keep it. Mathusam returns and tells everyone that he must return to space so the time has come for Goldar to defeat Rodak once and for all! Rodak overhears everything via the eyes and ears of his parrot-spy. Rodak plans to have all of the Earth’s volcanoes erupt at the same time. The space villain informs the people of Earth that a new creature will soon be coming and that they watch the tallest tower the next day at 8:00 AM. Rodak appears in person and then transforms into Kono, the mightiest monster in history! The call goes out for the Space Avenger— possibly for the last time!
Goldar faces a critical situation: he must kill Kono while at the same time saving an infant that is trapped in a building the monster is trying to destroy. Tom Mura can do nothing but try and hold back the frantic mother of the child, but Mikko calls for Gam as Goldar is fighting Kono. The boys fly into the building and save the child. Goldar takes off into the air, creating a heavy wind as Kono disappears. Goldar is followed to a volcano by Rodak, but the Space Avenger confronts the villain. Rodak turns into Kono— a mighty creature with super intelligence!! The volcano erupts and Rodak is injured, but escapes once again. Tom and Mikko return home only to find Rodak and his henchmen holding Tomoko captive. They take Mikko and his whistle to Rodak’s ship and head for space to set a trap for Goldar. Mikko breaks away and blows the whistle, summoning Goldar and Gam. Gam rescues Mikko as Rodak shoots a ray into Goldar, who loses control and drifts into endless space. Silvar and Gam get permission from Mathusam to go after Goldar. Mathusam contacts Goldar and instructs him to go to the planet where Goldar was created. On this world, Goldar will be able to gather new energy. Goldar locates the planet, but Kono is there! Dodging his way around Kono’s destructive “absolute zero” beam, Goldar absorbs energy from his home planet and finally kills Kono/Rodak! Back on Earth, Goldar, Silvar and Gam say farewell to their friends and head back into outer space. The threat of Rodak is gone, and the Earth is safe from the space villain for all time!
