Daiya Tsuwabuki is a boy in junior high who is known as the town liar. He claims that five years ago, he was saved by a large mechanical dragon when he and his father were attacked at sea by mechanical beasts. Even his mother and his only friend Naoto don’t believe his stories, but Daiya has physical proof of his experience, a mysterious device given to him by a young girl, a member of the mechanical dragon’s crew. Then one day, his town is attacked by two monsters, and the mechanical dragon, Daiku-Maryu, shows up. Daiya sees the girl who gave him the device years ago, and ends up in the dragon’s head, which transforms into super robot Gaiking, the Giant of Flame. Learning that he has control over the giant robot, he fights the enemy and drives them away from his town.

Daiya meets the crew of Daiku-Maryu, which includes Lulu, Gaiking’s supporter; Captain Garis; Vice Captain Rosa; Shizuka and Daimon in charge of the engine room; and Puria, the pilot of Stinger and the ace fighter of Daiku-Maryu. Puria does not yet accept Daiya and bullies him by beating him over and over in arm wrestling. Then suddenly the Demon Beast that they thought was already dead comes back to life and starts attacking the town again. Daiya, who becomes an official member of Daiku-Maryu, gets back on Gaiking and starts fighting the beast, and although he puts himself in danger because of inexperience, he manages to win with help from Lulu and Puria. Later, back on Daiku-Maryu, he learns that the enemy’s name is the Darius Army and that they come from the core of Earth.

Daiya learns that for their fight against the Darius Army, they have to go to the other world at the core of the earth, and Captain Garis gives Daiya some time to go say goodbye to his mother. Although his mother is relieved to see him alive, she is devastated to learn of his plans. While Daiya is still talking to his mother, he gets a call from Lulu, who tells him that Daiku-Maryu is being attacked by a Steel Beast. Puria comes to pick him up on the Stinger, and when they arrive on Daiku-Maryu, he jumps into its eye and onto Gaiking. After the battle, Daiya is upset that he has to leave his mother still heavy with grief, but feels encouraged when he sees her and Naoto standing on the shore to see him off.

In order to return to Darius, Daiku-Maryu must go through Death Cross Point and mend the subspace in order to prevent the enemy from going to the surface. The entry is an extremely harsh process, and Daiya, who is sitting in the Gaiking cockpit where the heat and pressure are worst, feels weak and nauseous. As they travel through the subspace, they run into a Demon Beast sent there by Saspazi, one of the four generals of the Darius Army. Since Daiku-Maryu is emitting energy to mend the subspace, it is not strong enough to counterattack the Demon Beast. Only Gaiking is capable of withstanding the heat, and despite the great danger of fighting in the subspace, Daiya takes Gaiking outside and manages to kill the enemy.

Daiku-Maryu arrives in Darius and goes to a regional city called Paltegona to stock up on food and supplies. Captain Garis orders Rosa to take Daiya and Puria into town with her in order to give them an opportunity to start getting along. In town, Daiya finds out that Daiku-Maryu and its crew are regarded as villains in Darius, a fact that has been bothering Puria for a long time. Daiya convinces her not to worry about what people think of them since it doesn’t change what they are there to do. Puria is impressed with Daiya’s way of thinking and opens up to him. On their way back to Daiku-Maryu, they are attacked by the enemy, currently under the command of Saspazi, who has no qualms about involving the citizens of Paltegona to serve his purpose. Gaiking, with support from other fighters, manage to drive the enemy away from Paltegona, but it does nothing to correct the misconception of its citizens, who believe that it was Daiku-Maryu who attacked their city.

Captain Garis temporarily assigns Daiya to five sections on the ship to decide which section he will join permanently. On the first day of the three-day trial, Daiya has a lot of trouble with the tasks of each section, especially when he has to run around Daiku-Maryu running errands for his bosses. But when he sees Lulu working hard at her job, he renews his determination and asks Shizuka of the Mechanic Team for advice. From the next day, he starts handling the tasks efficiently and even takes over for Lulu so she can get some rest. Then suddenly Daiku-Maryu is attacked by a Demon Beast, which breaks the Flare Tube, the passageway Daiya needs to get into Gaiking. But Daiya manages to get in by going outside the ship and jumping in through the eye. Using Rosa’s smart plan, Gaiking defeats the Demon Monster. Later, Daiya gets assigned to the Mechanic Team.

Daiku-Maryu docks at a tropical island where the crewmembers enjoy some beach time. Then from the other side of the island, they hear the sound of wild Demon Beasts, which are indigenous Demon Beasts that have not yet been made evil by the Darius Army. Daiya and the others go look for them when Saspazi drops a bio weapon on them to turn them evil. Then a Giant Soldier of the Darius Army, Lentes, piloted by Bliza, the former Northern Army general, arrives and starts killing the Demon Beasts as part of a pre-battle ceremony. Daiya hurries back to Daiku-Maryu, where he challenges the enemy Giant Soldier for a duel. Gaiking and Lentes start their duel but are interfered by Saspazi. Daiya, who comes to respect the honorable Bliza, challenges him to a rematch. But on his way back, Bliza is killed by Noza, the current general of the Northern Army, who blames him for disgracing his corps.

On their way to their fort in Ohmazan, Daiku-Maryu takes a break in the Kanalups Mountains. Puria, who gets into a foul mood watching Daiya and Lulu having a great time, decides to play a prank on Daiya and puts Pelps, mosquito-like insects of Darius, into his tent that night. The next day, when they are detected by a Steel Beast search unit, Stinger and Gaiking are ordered to launch, but Daiya shows an abnormal reaction to the Pelp bites and passes out before he can get on Gaiking. Puria feels guilty about it but can’t get herself to confess and apologize. Then another Steel Beast attacks Daiku-Maryu. At first, Puria tries to fight it off by herself but is saved by Gaiking when she gets hit by the quick enemy. Then Daiya and Puria learn that Gaiking and Stinger can combine to become Sky Gaiking. Puria, who remembers Rosa’s advice on how to relate to people who have powers that she doesn’t, shows excellent teamwork with Daiya during the battle, and she later apologizes to him for the prank.

One day on their way to the Ohmazan fort, Daiku-Maryu is attacked by a giant turtle beast, Domega. During the battle, Daiya and Lee try to combine Gaiking and Serpent to become Buster Gaiking, but Lee fails in the attempt. Later, Daiya learns of Lee’s past with Domega: years ago, the Demon Beast had killed Shin, who was like a little brother to Lee, and to avenge his death, Lee had joined Daiku-Maryu. After that, Lee had once forced his way onto Gaiking, only to be defeated again by the same Demon Beast. Now after this third loss to Domega, Lee resigns from Daiku-Maryu and goes to a nearby village to look for work where he runs into an old man who informs him that he had saved their lives years ago when he fought Domega on Gaiking. Lee is moved to find out that he was able to save an entire village despite being defeated by the Demon Beast at the time. Then they see Domega attack the Ohmazan fort, and Lee decides to go back and fight. This time, he successfully combines with Gaiking and avenges his little friend.

As Daiku-Maryu approaches the dark continent of Arkholand where the Darius Army headquarters is located, Lulu starts having nightmares about her childhood and the black flame. She starts losing sleep and feels under the weather. Then, off the coast of Arkholand, Daiku-Maryu gets caught in an invisible barrier made from a substance that drains power out of Daiku-Maryu and Gaiking. In order to extinguish the barrier, they must destroy its source of energy located at the bottom of the sea. Captain Garis orders Lulu to go on the mission, and Daiya, horrified that the captain could be so heartless, accompanies her. Once underwater, Gaiking combines with Krab Bunker piloted by Lulu and becomes Diver Gaiking. Although Lulu manages to locate the energy source, she falters when she has a flashback of her fearful past and the black flame. Garis and Daiya encourage her to overcome her fate, and she successfully shoots down the energy source.

One day, Grotecter warships of Northern General Noza fly past Daiku-Maryu. They are on their way to create another Death Cross Point, the hole that connects to the world above the surface. Gaiking and the other Daiku-Maryu fighters try to stop them, but they are met by two Northern Knights, Misha and Rick, on their Giant Soldiers. Daiya is taken aback by their fighting style, which defies the code of chivalry that the honorable Lord Bliza upheld. Then Noza, who finds out that Misha and Rick did not inform him of their launch, shows up on his Giant Soldier, Dorman, and kills them on the spot. He challenges Daiya to a duel, which Daiya accepts despite Garis’s desperate plea that he flee from the scene. Daiya fights with every attack and weapon he can think of but is no match against Noza. Then suddenly, he remembers his father, and his flame gets stronger. With an ultra strong Hydro Blazer, he manages to drive away Noza for the time being. Then when he returns to Daiku-Maryu, Garis congratulates him and pats him on the head the same way his father used to, which makes him wonder about Garis’s identity.

While Grotecter warships are forming Death Cross Point, Noza challenges Daiya to another duel. Daiya goes against Garis’s order and accepts, even though he is daunted by Noza’s strength. When the duel begins, Noza overwhelms Daiya, but Daiku-Maryu shows up at the battlefield and starts attacking the Grotecters. Noza is baffled by Garis’s action since he usually does not fight this way, but Garis is desperate to protect Daiya. Backed up by his men’s three Zerunga Giants, Noza continues to overpower Gaiking until Daiya decides to use a powerful technique that he is still forbidden to use. Although he had promised Lulu that he wouldn’t use it, his strong desire to protect his beloved crewmates and the captain, who he thinks is his father, is too strong to stop him. Gaiking transforms into Face Open Gaiking and defeats Noza in this battle. However, the forbidden attack leaves Daiya unconscious in the cockpit.

After the battle with Noza, the captain and Daiya fall ill, and Daiku-Maryu, as well as Stinger and Serpent, are badly damaged. Captain makes Lulu command the ship in his absence, and reveals his identity to Daiya. Contrary to what Daiya thought, Captain Garis is not his father, but a former scientist from Darius who designed and built Daiku-Maryu. Then Noza attacks again with his new-and-improved Giant Soldier Dorman. Daiya gets up and goes back into battle. And with the new device that Shizuka developed for him which displays the time limit to safely stay in Face Open, he defeats Noza.

After the battle with Noza, Daiku-Maryu and Gaiking get repaired in a new fort built by rebel forces in an abandoned desert city. There, in an amusement park, Lulu and the others see Vice Captain Rosa sighing and acting strangely in front of a merry-go-round, which makes them worried that she might be feeling stressed from working too hard. Lulu, who accidentally found and read Rosa’s diary, tells them that Rosa writes about her hardships on the ship, especially ones concerning Daiya. So the crewmembers reactivate the amusement park in order to let Rosa have some fun. But while they are enjoying the rides, the enemy attacks. Daiya starts fighting on Gaiking, but since Gaiking isn’t fully repaired yet, he can’t use any of the energy weapons. Then Rosa, who analyzed centrifugal motion on the rides in the amusement park, asks Dr. Sakon to apply her calculations to defense system Volution Protect, which turns Daiku-Maryu into a huge offensive weapon. After they win the battle, Rosa reveals that the “hardships” in her diary aren’t really hardships at all, but are records of her fulfilling days on Daiku-Maryu.

During a battle in the air, a civilian airplane asks Daiku-Maryu for help, and Lulu agrees to let him come onboard. The pilot, a Darius man named Jan, demands to be taken to the surface world and tries unsuccessfully to hijack Daiku-Maryu. He later tells Daiya that he saw a man from the surface who looks a lot like Daiya in a village nearby. Daiya and Lulu take Jan to the village, only to find it abandoned and seized by Darius soldiers. Jan manages to flee, but Daiya and Lulu, who find out that Jan is wanted fugitive, are captured. They are taken to a mine, where the villagers are being forced to work. Then Proist, who is the one operating the mine, orders his men to blow it up since Vestarnu is on her way there. Daiya and Lulu help the villagers escape, but find out that there’s second mine in which the man from the surface is laboring. Daiya, aided by Jan, who comes back to help Daiya, fights the Steel Beast that gets in his way and saves the villagers from the second mine. Later, Daiya finds out that the man from the surface is not his father but is his assistant, who informs him that his father is captured by the Darius Army but is indeed still alive.

One day, Lee goes on a recon mission and saves Vestarnu, who is being attacked by droid soldiers at Proist’s secret quarry. She gets gunpowder in her eyes and becomes temporarily blinded. Lee lies to her about his identity, and helps her escape the droid soldiers but not before calling Puria and Daiya for help. On their way to help Lee, Daiya and the others run into Noza, who now has a new Giant Soldier called Bareon. Although Daiya is in a hurry to get to Lee, he tells Puria and the others to go on ahead without him while he fights Noza. During the battle, however, Noza suddenly feels an intense pain in his chest, which allows Daiya to leave the scene and go to Lee. Later, Gaiking combines with Stinger, Serpent, and Krab Bunker to become Triple Gaiking. Meanwhile, Noza finds a mysterious device in his chest, which seems to be causing the intense pain, and Vestarnu’s suspicion of Proist increases.

Daiku-Maryu arrives in the lawless city of Zangyle. Captain Garis tells Rosa to oversee the ship while he goes into town. Accompanied by Puria, Lee, and the mustache trio, Garis visits a casino, where a young man named Dick is waiting for him. Dick, a member of Daiku-Maryu, temporarily left the ship a year ago after he lost a bet with Garis. He challenges the captain to another bet over Daiku-Maryu, but at that moment, Daiya, who is supposed to be waiting on the ship, is brought to the room by Dick’s underlings. Dick realizes who Daiya is and turns the bet into a match over Gaiking. Daiya, entrusted by Garis to make the bet, beats Dick in a game of roulette when suddenly Steel Beasts of the Darius Army attack the city. The Daiku-Maryu crewmembers return to the ship and fight back on their machines. However, Gaiking gets captured by one of the Steel Beasts, rendering the others helpless. Then Dick, with his machine named Killjaguar, shows up and helps them destroy the enemies. However, after the battle, another Steel Beast appears and tries to pull Gaiking into the sea. Then Dick suddenly attacks Gaiking.

Dick attacks Gaiking to get to the enemy, and while the enemy falters, Gaiking counterattacks. Although they managed to get through the battle, everybody is furious at Dick for his dangerous tactic. Nonetheless, he is popular with the women on Daiku-Maryu with the exception of Puria and Rosa, who refuse to accept him, and Lulu, who is unsure of her feelings toward him. Later, after an unsuccessful training session for fighting a team battle, Hyper Steel Beast Graneps in its perfected and most powerful form shows up. It attacks Gaiking with an ice beam produced from Rogueflute, a new mineral discovered by Proist that renders Gaiking’s flame power useless. Gaiking gets frozen up with the new attack, and Proist celebrate their victory by revealing his, or her, true identity – a creature that looks like a beautiful woman but is of neither gender and who is apparently the child of Emperor Darius.

Powerless against the enhanced Steel Beast, Stinger, Serpent, and Killjaguar retreat to Daiku-Maryu for the time being, but they learn that Proist ordered a public execution for Gaiking. The only way to revive Gaiking’s flame power is with a weapon called Hydrute Arrow, but it can only be done with perfect teamwork among Puria, Lee, and Dick. Worried sick about Daiya, Lulu begs Dick and Puria to cooperate with each other. Dick agrees on condition that Lulu let him kiss her if they succeed. Puria is still reluctant to work with Dick, but Daiya and Lee, who have come to notice Dick’s good side, convince her to cooperate. They finally succeed with Hydrute Arrow, reviving Gaiking and destroying the Steel Beast, and later, back on Daiku-Maryu, Gaiking, Stinger, Serpent, Killjaguar, and their pilots are officially appointed as the Combat Force. Meanwhile in the Darius Army, after Noza discovers that he is being cloned as Proist’s spare body, he becomes dejected and turns completely submissive. Then Emperor Darius gives complete command of the Darius Army to his child and successor, Proist.

One day on a deserted island, Garis proposes a race to go find Windarium, a mineral ore that can counterattack Darius’s ice beam. The winner will become the Daiku-Maryu captain for a day, and ten crewmembers decide to participate in the race. Each of them is given a mini machine to go look for the ore. The race begins, and Daiya, Puria, and Dick are the only ones left in the end. But a Demon Beast appears and gets in their way. Daiya, Puria, and Dick cancel the race and fight the enemy with good teamwork, which delights Combat Force leader Lee, who actually came up with the idea of the race to foster teamwork among the three pilots. Later, back on Daiku-Maryu, Garis announces the winner of the race, which is Lulu.

Lulu starts reading people’s fortunes when one day, she predicts that Bry, the rebel fighter and Daiku-Maryu supporter, will reunite with someone special. Meanwhile, Daiya gets jealous watching her read fortunes for other people. Prompted by a mischievous Puria, Daiya makes a scene and tries to make Lulu quit telling fortunes, which badly hurts her feelings. Later, they are contacted by Bry’s daughter Shion, also a rebel fighter, who stole transport vessels from the Darius Army. They decide to join up at a prairie near the enemy stronghold without knowing that a trap has been laid there by Proist. Caught in the trap, Shion selflessly tells the Daiku-Maryu crew not to worry about her and to attack. Lulu decides to go out in the battlefield with the other fighters to try to find Shion, but she has trouble detecting her flame because of Daiya’s selfish remark earlier. But after Daiya’s sincere apology, she gets her power back and finds Shion, and they blast their way out of the trap.

One day, Yanma, Haccho, and Booby, in an attempt to prove their usefulness, force themselves onto Gaiking with Daiya. But Gaiking gets captured by the enemy, and Daiya and the trio are taken back to the enemy warship. There, the trio is dumped like garbage down a garbage shoot, but Daiya escapes and gets back onto Gaiking. However, a Demon Beast controlled by Saspazi gets into the cockpit with him and takes control of his actions. Then Saspazi starts making Gaiking attack Daiku-Maryu, and the trio, who manages to get out of the garbage shoot, try to redeem their honor by destroying the machine that is connecting Saspazi to the Demon Beast in Gaiking’s cockpit. However, their plan fails, and they get ready to face their end as enemy soldiers surround them. But when they see Puria coming to rescue them, the flame in their hearts burn strongly, and they succeed in their special three-as-one attack to break down the machine. Daiya, now freed from the Demon Beast, attacks and destroys the enemy warship. Yanma, Haccho, and Booby survive the explosion, and later back on Daiku-Maryu, they start calling Daiya their “aniki” (older brother or male of senior status).

One day, Shizuka looks frantically for Dr. Sakon, but he is nowhere on the ship. Shizuka becomes furious and takes off on Stinger to go find him. Meanwhile, Daiya learns that Sakon used to support and encourage Shizuka when she used to be the Stinger pilot many years ago. Since then, Shizuka has continued to look after Sakon, although he complains about how pushy she is. Then some Steel Beasts penetrate Daiku-Maryu and attack Garis, Daimon, and Dr. Franklin by detecting their life signals. At the same time, the same Steel Beast attacks Sakon, who, together with Daimon and Franklin, used to work for the Darius Army before they joined Garis on Daiku-Maryu. Gaiking, Serpent, and Killjaguar find Sakon just in time to protect him, but the Steel Beast disappears from their sight. Sakon volunteers to lure the Steel Beast with his life signals, and the Combat Force successfully destroys it without harming Sakon. Later, Sakon lets Shizuka call her mother back home on the surface with a new machine he developed, and he also shyly admits that he is actually grateful for the attention she gives him.

The Daiku-Maryu crewmembers start seeing pink hippos everywhere on the ship. Dr. Franklin informs them that they are hallucinations from Limitation Syndrome, which occurs when people feel stressed out. He says that the cure is a little recreation, so the crew decides to hold an idol contest to alleviate their stress. Rosa, Puria, Shizuka, Lulu, and Kyoko from the galley are the idol candidates, and the winner is to be decided by a popularity vote by the rest of the crew. In the contest, each candidate receives the same number of votes, and the match goes into the second round, which is a cleaning contest. The one who collects the largest amount of trash will win. The winner will become the idol, and Daimon, who used to be an aspiring folk singer in his youth, will produce the song for her. The candidates, with help from their supporters, start cleaning the ship, but an enemy warship approaches.

The Daiku-Maryu idol contest enters the final round in which the candidates become an idol for the deciding popularity vote. They each make a performance that will attract the crew’s attention. Puria becomes a rock singer. Rosa becomes an enka singer. Kyoko serves dessert. Shizuka shows her usually hidden face. Only Lulu is reluctant to compete because she feels sad about the fierce rivalry among the candidates. She pleads with them to stop the fighting, and the others come to their senses. They decide to step down and let Lulu become the Daiku-Maryu idol. Just as Lulu’s victory is announced, the enemy attacks. Then Lulu sings a song during the battle and encourages the crew, making the pink hippos from Limitation Syndrome disappear.

Concerned about Captain Garis’s odd behavior, Dick and Daiya take off on a surveillance mission and land in a ruined city. There, Dick runs into Proist, and Daiya into Noza. Instead of starting a battle right away, Noza tells Daiya, who had come on a Banza, to call Gaiking so they can fight on their Giants. When Gaiking arrives, Daiya and Noza begin their battle. Meanwhile, Proist changes into a special suit and calls up a machine that looks exactly like Daiku-Maryu. Proist then enters a Giant named Vulking and starts attacking Gaiking and Daiku-Maryu. When Gaiking is about to be hit by a huge drill fired by Vulking, Noza intercepts and protects him. Daiya takes the opportunity to take the drill from Noza, and counterattacks, managing to drive Proist away for the time being. Later, back on Daiku-Maryu, Shizuka learns from Sakon that the enemy’s machine that looked like Daiku-Maryu is called Daichi-Maryu, a proto-type of Daiku-Maryu. He also tells her of another proto-type, Tenku-Maryu, and mentions that these two machines have a secret tragic past.

Daiku-Maryu gets attacked by Vestarnu and her Steel Beasts, and Lulu gets kidnapped. To get her back, Proist tells Garis to come alone to the place where he hid Tenku-Maryu. When he arrives there, Proist demands the password that awakens Tenku-Maryu in return for Lulu’s life. Garis agrees and says the password, Eltrika, which is Lulu’s mother’s name. Tenku-Maryu wakes up and attacks Daiya, Puria, and Lee on Serpent Buster Gaiking, who came to rescue Garis and Lulu. Meanwhile, Proist releases Lulu as promised, but when Garis’s mask falls off when he fights the Steel Beasts, Lulu recognizes him as the man who killed her mother when she was a young child. Garis admits that he indeed killed her mother, his wife, thereby revealing that he is Lulu’s father. In a state of shock after the revelation, Lulu lets Proist talk her into avenging her mother and stabs Garis with a dagger.

Dick intervenes just in time and takes the blade in the shoulder instead of Garis. Lulu gets taken away again by Proist, and Garis and the others return to Daiku-Maryu. There, Sakon, Daimon, and Franklin reveal Garis and Lulu’s secret. Garis, who used to be the Science Minister of Darius, escaped the Darius Army with Sakon, Daimon, and Franklin, who were being forced to help build Daiku-Maryu, Tenku-Maryu, and Daichi-Maryu. They also stole the three Maryus and sealed away Tenku and Daichi. A female scientist, Eltrika Arjes, also escaped with them and fell in love with Garis, and together they had Lulu. However, Proist, who became enraged at Garis for having a child with a surface dweller, shot and killed Eltrika. Lulu lost her memory from the shock of seeing her mother killed, and Garis started blaming himself for the tragedy. Since then, he has hidden his identity and looked after Lulu as the captain of Daiku-Maryu. Back in the present, Garis goes to the place where Eltrika was shot to go find Lulu. Daiya and the others also come to help, and after a fierce battle against Tenku-Maryu and its Giant Raiking, they manage to drive the enemy away. Lulu also gets back her memory and remembers that it was Proist who killed her mother.

Garis must be taken to a rebel fort to get treated, but in order to get there, Daiku-Maryu must fly through a dangerous minefield. Shion of the rebel army contacts Daiku-Maryu and asks them to send Garis to a meeting point to expedite his arrival at the fort. Ignoring Rosa’s decision, Lulu and Dick take off on Kani Tank to take the captain there, but when they arrive, they are attacked by Tenku-Maryu, Raiking, Daichi-Maryu and Vulking. Earlier, Saspazi had tricked Proist into making her believe that he was her loyal servant, and won the chance of piloting Vulking. However, during their attack on Kani Tank and Gaiking at the false meeting point, Saspazi turns on her and starts attacking Raiking. He fails however and is killed instead. Meanwhile, Daiku-Maryu makes it to the rebel fort in time for Garis to receive his treatment.

Daiku-Maryu docks by a beautiful lake, and the crewmembers enjoy a moment of relaxation. There, Daiya compares his friend Naoto and his video games to their battle against Raiking and Vulking. As Daiya tries to persuade the crew to put their hearts together to fight the enemy, Lulu, the new captain of Daiku-Maryu, further encourages everybody. With renewed spirit, Daiku-Maryu and its crew take on the enemy in an all-out battle. They fight with good teamwork and high spirits until Raiking appears. Daiya notices something different about it and realizes that it’s Noza who’s piloting the enemy Giant. Although Daiya used to be terrified of him, he can’t get himself to fight back because of a mutual respect they had begun to develop over the last few battles. Meanwhile, Proist brainwashes Vestarnu and prepares her to fight on Vulking.

Lee infiltrates Daichi-Maryu and finds a way to undo the brainwash on Vestarnu. He tells Daiya to do the same thing to Noza. Shizuka and Sakon overtake Tenku-Maryu, and now the three Maryus and the three Giants of Flame are under their control. Then Proist calls out an evil Super Maryu, Dvorzak, and counterattacks. The Daiku-Maryu team uses all their combat force to fight the Super Maryu but cannot defeat it. A desperate but determined Daiya is about to use Open Face for the second time when Sakon stops him and tells him about Gaiking the Great, a combination of the three Giants’ strongest parts. Supported by the crewmembers’ flame and spirit, Daiya defeats Dvorzak on Gaiking the Great. The Daiku-Maryu team enjoys a brief moment of victory, but suddenly a black shadow sweeps away Daiya and Gaiking into Death Cross Point that Proist produced earlier during the battle.

Daiya and Puria are blown away to the surface on Gaiking’s torso and Superior Stinger. They find themselves on a deserted island but don’t have enough flame in their machines to fly anywhere. Then an aircraft comes and lands on the island. It brings Cherry and Ben, Darius people and Daiku-Maryu supporters on the surface who take care of the crewmembers’ families. Daiya’s friend Naoto is also with them. Then a Steel Beast suddenly attacks from the sea. Cherry tells Daiya and Puria to buy some time until makeshift Gaiking parts get transported to the island on a cargo ship. When they arrive, Daiya and Puria combine with the Gaiking parts to become Sky Gaiking, but this Gaiking isn’t as strong as the real one. They nonetheless defeat the Steel Beast, and name the proxy Kaikink.

When Kaikink is fixed, more Steel Beasts attack the cargo ship. Then suddenly, Killjaguar and Daiku-Maryu show up and join the battle. They destroy the Steel Beasts, and Daiya and Puria go back onto Daiku-Maryu. There, they learn that Sakon figured out a way for Daiku-Maryu to enter the surface and that Lee stayed behind in Darius to fight with Vestarnu, now an ally. Naoto also comes onboard, and is taken on a tour of Daiku-Maryu by Yanma, Haccho, and Booby. Then more Steel Beasts attack. While Gaiking, Stinger, and Killjaguar are fighting back, another huge Steel Beast attacks Daiku-Maryu. Rongo, who is wounded badly from an earlier battle, cannot maneuver the ship, and a determined Naoto takes the helm in his place. After the battle, Lulu invites Naoto to stay onboard as the 48th crewmember of Daiku-Maryu, and he accepts. Meanwhile in Darius, Emperor Darius reopens something called Operation Ark, and Proist starts something called the FD Operation.

Daiku-Maryu heads toward the coast of California looking for the remnants of the Super Maryu. When a Steel Beast approaches the ship, it is shot down by US Navy submarines, which were commissioned to back up Daiku-Maryu by the chairman of NEX, the company that Cherry and Ben work for. Later that day, the crewmembers attend a welcome party hosted by NEX in Los Angeles. Dick, who is actually the son of NEX’s chairman, Roberts, takes Lulu away from the party and out into the city. He takes her to the house where he used to live, but Roberts shows up with replicas of Darius droid soldiers produced at his factory. He tells his son and Lulu that he switched sides to Darius since he believes Daiku-Maryu cannot win without Garis. Then a Steel Beast attacks Daiku-Maryu and the city, and Dick on Killjaguar defeats it.

Daiku-Maryu returns to Darius with a special missile that creates Death Cross Point. They join up with Lee and Vestarnu on Daichi-Maryu and head toward Darius Capital. Daiya finds out from Vestarnu that his father used to be in a prisoner camp in the capital, but when they get there, the camps are already empty. Meanwhile, much to her anger, Proist finds out that her father, Emperor Darius, is proceeding with Operation Ark, and she moves up her Operation FD to the final stage. Using the Darius Core, an energy mass that maintains the balance of Darius World, she plots to sink the capital. Gaiking, Vulking, Stinger, and Killjaguar try to help the citizens that are left there, and later, they are joined by Noza, who is still alive, on Raiking. Then Gaiking transforms into Gaiking the Great with parts from Vulking and Raiking, and save the capital. Daiya asks the citizens if anybody knows a man named Tsuwabuki, but his father seems to have been taken elsewhere. At the same time, Vestarnu, who analyzed some new data, informs Lulu that Daiya’s father is on a science team that reports directly to Emperor Darius.

Emperor Darius contacts Lulu and asks her to stop Proist. He asks for a meeting and says he will bring Daiya’s father with him. Lulu thinks that it may be a trap, but decides to meet him anyway. Daiku-Maryu team heads toward the designated ice field, where Darius and Daiya’s father, who now goes by Dr. Two, await them. Daiya is relieved and happy to see that his dad is still alive when Proist suddenly shows up. Thinking she was betrayed by her own father, she turns into her male personality and kills Darius. When she snaps out of her rage, she forgets what she did, and blames Darius’s death on Daiya and his dad. She takes Daiya’s dad away into her warship and promises to punish them in the cruelest way possible.

Proist puts Daiya’s dad in a pod inside the Super Maryu Beast, Final Dvorzak. The pod is connected to the beast’s heart with cords, and when Daiya tries to pull it out, some cords break, making his dad feel excruciating pain. Then Proist explains that when the last cord is broken, the pod will explode in 30 seconds. But Sakon finds an organ behind the beast’s heart that will deactivate the detonator. However, thinking he might hit the pod by mistake, Daiya is too afraid to attack. Then his dad pulls out the cords himself and scolds Daiya for running away from the battle. Encouraged by his words and an experience from childhood, Daiya destroys the beast and saves the pod before it explodes. However, the beast is not completely dead yet and attacks when Daiya has his guard down. But Dick on Killjaguar intercepts the beast’s attack, and dies.

Lulu is devastated over Dick’s death and refuses to command the ship until Rosa makes her come to her senses. Daiya returns to Daiku-Maryu for refueling and have a tearful reunion with his father. He goes back out to finish the battle against Proist, who has entered the giant Darius Robot. While Gaiking and Darius Robot are fighting, the rest of the Daiku-Maryu crew work together and support each other to rescue the Darius Core and the people left behind in Proist’s giant fortress. Then Gaiking transforms into Gaiking the Great, and empowered by the crewmembers’ and allies’ thoughts and will, Daiya finally destroys Proist and Darius Robot.

Proist comes back to life after her four generals sacrifice their lives for her. She shows up in Daiku-Maryu, and turns into a demon out of jealousy and rage when she sees Daiya with his dad and Lulu with her dad, Garis. Her uncontrollable fury comes to a peak when Sakon tells her the truth about the emperors of Darius—that she is merely a container for the souls of previous Darius emperors. But Daiya stops her black flame with his red flame, and Proist finally meets her end. Peace is restored to Darius and the surface world, and Operation Ark is launched to transfer the people of Darius to a new homeland. Lulu and part of the Daiku-Maryu crew take off to outer space, while Daiya, Naoto, and Puria stay behind on Earth. However, five years later, Lulu contacts Daiya again and says they need his help once again. And so, Daiya takes off on another journey of adventures on Daiku-Maryu.