Yapool, an ancient inter-dimensional creature from ancient times with similarities to Satan and Legion, sought the planet of Earth and tried to conquer it with a campaign that involved his experiments known as Choju. The first super weapon sent to Earth, Velokron, ravaged a city and took on TAC, a special forces unit created by the Self Defense Force to defend the Earth from kaiju. Two of Velokron's unfortunate victims were Seiji Hokuto and Yuko Minami. The first five Ultra Brothers, Ultraman, Zoffy, Ultraseven, Ultraman Jack, and Ultraman Ace, decided to revive the duo for trying to help young children get away from the Choju and to fight off Yapool's forces.
Ace decided to be the one to go as he had both of them be his host. Yapool has used not only Choju, but also recruited other aliens, humans that sold their souls to him for Choju possession, and even himself, to assassinate Ace and TAC only to be brought down in absolute defeat. After the destruction of one of Yapool's oldest Choju, Lunatyx, Minami revealed she was one of the last natives from the moon and gave her Ultra Ring to Seiji as she had to leave, but promised she would return every once in a while.
Ever since, Seiji has been Ace's only host and their efforts were just the same. Yapool became desperate by combining the bodies of a selected few choju to create Jumbo King only for him to fail and have Ace fly off to his home world of Nebula M-78. Ever since, Ace has appeared to help later Ultras in their times of need. Ultraman Ace still retains a connection to Seiji as his human host, as seen in Ultraman Mebius series and subsequent movies.
After defeating Alien Hipporito and reviving the Ultra Brothers, Ace and the Ultra Brothers took the Father of Ultra back to M78 after ripping off his Color Time to revive Ace, and while Ultraman Taro fights Enmargo, Juda summons Grand King. The Ultras saw him coming and lured him to another planet. While the Ultra Brothers were completely decimated by Grand King, Father of Ultra awakens and says Taro is the only one able to defeat it.
The Mother of Ultra tells Taro this, enabling him to defeat Enmargo. He flies to the aid of his brothers. Then Mother of Ultra tells them they must channel their energy into Taro's horns. They do so and vanish, and Taro becomes a super Ultra. He soon defeats the monster and Juda vanishes. He restores the Ultra Brothers back to their forms, and they return to the Ultra Star. Father of Ultra is recovered and they all have an inspirational conversation, with Taro becoming a member of the Ultra Brothers. Ultraman Story
After the sacrifice of Kotaro Higashi after being killed by Astromons, Ace along with the Ultra Brothers and Mother of Ultra bring him to M78 and provided energy to help revive Kotaro and have him be Taro's host. Like the Sun, Mother of Ultra
After Taro retreated after being hurt by Mururoa and went to the Land of Light, Ace, and the Ultra Brothers were waiting for Taro when he arrived. They all went to retrieve the only item which could clear the space monster's smoke, the Ultra Bell. Taro and the Ultra Brothers arrived, pulling the Ultra Bell with them. The legendary device’s tolling cleared away Mururoa’s darkness in an instant. After Mururoa was defeated, Taro returned the Bell. Burn On! The Six Ultra Brothers
Ultraman Ace joined the battle against Alien Temperor after visiting Earth and Taro with the Ultra Brothers. 5 Seconds Before the Great Explosion of the Land of Ultra! The Last Day of the Six Ultra Brothers!
Ace fought Tyrant on Mars after Ultraman, Zoffy, Seven and Jack were defeated. Ace, like his brothers, was defeated by Tyrant. Luckily, Ace was able to emit an Ultra Sign to warn ZAT and Ultraman Taro of the coming kaiju's presence. Go Beyond the Ultra Brothers!
The evil alien Babalou managed to freeze Astra, Ultraman Leo's younger brother, and later disguised himself as him. "Astra" flew to the Land of Light, and after being followed by the Ultra Brothers (Ultraman, Zoffy, Ultraman Jack and Ultraman Ace), he manages to steal the Ultra Key. The Ultra-homeworld fell out of its orbit, and was heading towards a direct impact with Earth. When he was going to escape, he was stopped by Ultraman, and the two had a short fight, but "Astra" escaped and flew to Earth. The other brothers raised Ultraman from the ground, and he said that it wasn't Babalou who stole the Ultra Key, but "Astra", the Ultras were shocked, and they all flew to Earth following him, not before informing Ultraseven that "Astra" took the Ultra Key. Dan Moroboshi told Gen Ohtori about what happened, Gen was shocked, and after "Astra" arrived on Earth, Dan tried to stop him using his Ultra powers, and the Ultra Brothers arrived on the scene. Gen stopped Dan, and the two started to fight, as the Ultra Brothers started to fight against "Astra.
Ultraman managed to hurt "Astra" and make him fall, but he stood up. After Gen Ohtori and Moroboshi stopped fighting, he used his Ultra powers and made "Astra" weak. Hearing "Astra's" cries, Gen recovered and beat Dan to unconsciousness, afterwards transforming into Ultraman Leo. After a hard battle against the four Ultra Brothers, he questions "Astra", asking him what he did but "Astra" didn't answer. Leo tells the Ultras to stop, but they said they couldn't since stealing the Ultra Key may cause the Land of Light to hit Earth, destroying both. At that same moment, the Land of Light was close to Earth, and natural disasters started to occur, earthquakes and fissures were occurring. The Ultra Brothers started to fight both Leo and "Astra". After a short battle, the Ultra Brothers had no choice but to use their Specium Rays against "Astra". They fired them at him, but Leo protected "Astra" and took the damage, falling to the ground completely hurt. "Astra" menaced the Ultra Brothers, about to shoot a beam from the Ultra Key, but suddenly, a mighty lightning bolt from the sky flashed near "Astra", and he fell to the ground, the Ultra Key broke into two pieces. Ultraman King appeared, and after saluting Zoffy, he told the Ultras to watch out for "Astra", firing his ray to reveal the fake Astra as Alien Babalou. Leo defeated Babalou after recovered the real Astra from his imprisonment and repaired the Ultra Key and then gave it back to Ultra Planet, and Ultraman Leo and Astra became the first members from the Space Garrison that were not born in the Land of Light. Battle! The Leo Brothers vs. the Ultra Brothers! The Leo Brothers and the Ultra Brothers, Time of Victory
The 6 Ultra Brothers vs. The Monster Army
After Piko was killed by some robbers, Mother of Ultra took him to the Land of Light to revive him. During the resurrection process, the Ultra Brothers were present, and using their energies, they transformed Piko into the monkey god, Hanuman.
Many moments later, a Thai base was trying to launch some missiles to the sky, because it would stop the worldwide drought, and cause rain. A missile was shot, it exploded in the sky, and it caused rain, as expected, but as the second missile was shot, it had a problem, and after failing to blast off, it blew up, causing a chain reaction with the other missiles, causing an apocalyptical event, and five monsters (Gomora, Tyrant, Dustpan, Astromons and Dorobon) rised from the Earth, and started causing chaos. Hanuman appeared to fight the monsters, but after receiving too much damage from them, the Ultra Brothers suddenly appeared from the sky, and they all start fighting the monsters. After they were all defeated, Gomora, who was unconscious, wakes up, and after climbing a mountain, releases a rainbow beam that caused catastrophic natural disasters. Ultraman and Hanuman were trying to stop him, but the beam was too powerful, and they couldn't get close. Suddenly the other Brothers arrived, and managed to interrupt Gomora's beam. After Gomora was defeated, peace reigned again, and Hanuman said good-bye to the Ultra Brothers, who flew back to the Land of Light. The 6 Ultra Brothers vs. The Monster Army
Ultraman Mebius and the Ultra Brothers
In 1986, Ultraman, Seven, Jack and Ace were fighting the choju U-Killersaurus after a rough battle on the moon. When the Ultras were about to launch their rays at the enemy, Ultraman alerts them that if they fire and miss, their rays would destroy the Earth, so the Ultras threw the monster into the sea next to the city of Kobe. The heroes decided they only way to defeat the Choku and Yapool, was to seal it in the sea with the Four Cross Shield, but at the cost of not being able to transform in their Ultra selves. They used the Final Cross Shield, and the monster was sealed along with Yapool, and peace reigned on Earth for many years.
Then 20 years later 2006, Ace's Human Host Seiji Hokuto became a head chef at a restaurant. Hayata invited Mirai on a boat where the rest of the Ultra Brothers, and their Human Hosts were. Then when Ultraman Mebius was fighting Imitation Mebius Hayata and the others watched. After Mebius defeated Alien Zarab, he was surprisingly attacked by Alien Guts, was defeated, and sealed in a cross of crystal. Seiji (Ace) argued to help Mebius, but Hayata refused. However, after a short while, they all agreed to help out the younger Ultra. The Ultra Brothers then transformed once again. The brothers fought for about 1-2 minutes with their low energy, despite the seal, but because of their limited power, they were defeated by Guts and Alien Nackle, and they were all crucified in glass crosses above Kobe's sea where Yapool and U-Killersaurus were sealed. Guts and Nackle then threw Mebius away and drained the remaining energy from Ultraman Ace and the other Ultra Brothers.
While seeing his fellow Ultras in pain, Mebius found new strength after being encouraged by a young boy whom he befriended prior to the battle, and the teachings of the four Ultra Brothers. He then returned to the fight, with great courage. He managed to destroy Alien Guts, and freed the Ultra Brothers, but not in time as U-Killersaurus and Yapool were already freed from their prison. Once freed, the Yapool killed and betrayed Alien Nackle and upgraded the U-Killersaurus to U-Killersaurus Neo. Ace stated that Yapool was a real devil.
The powerful Chouju easily beat down the weakened Ultras, until surprisingly, Commander Zoffy, and Ultraman Taro arrived and entered the fray. Taro and Zoffy quickly restored their fellow Ultra's energy, but even at full power they still could not defeat the monster. They decided to give their light to Mebius to finish the battle. Ultraman Mebius, combined with the other Ultra brothers, transformed into Mebius Infinity, and defeated the Choju once and for all. Ultraman Mebius & the Ultra Brothers
Ultraman Ace reappeared in Ultraman Mebius
When Mebius was defeated by his old enemy Yapool, Seiji telepathically contacted him and told him that if he has someone that is precious to him, he can and will overcome any foe, which gave him the strength to rise again allowing the young Ultra to defeat the other dimensional demon. Ultraman Ace talked to Marina of GUYS saying they should destroy the towers. When they tried to, only to be menaced by Lunaticks, Seiji transformed into Ultraman Ace and arrived at the moon. Ultraman Ace fought the monster and finished it with the Metallium Ray. Once the battle is finished, Yuko greets him once again and transforms. Ace's Wish
Ultraman Ace was also with the Ultra Brothers to destroy the Sunblock that was covering the sun with the Metallium Ray and was seen with Ultraseven at the end before flying back.
Mega Monster Battle: Ultra Galaxy Legends The Movie
Ultraman Ace joins Ultraman Jack and Ultraman 80 in trying to fend off the evil Ultraman Belial from reaching the Plasma Spark while they are inside the Spark Tower itself. Despite the three Ultras' combined efforts, Ultraman Belial brushed off their assaults and defeated all three of them with the Giga Battle Nizer. Ultraman Ace was then frozen along with the Land of Light and its population when it froze over after Belial stole the Plasma Spark, however he was freed along with them when the Spark was returned by Ultraman Zero. Mega Monster Battle: Ultra Galaxy Legends The Movie
Ultraman Zero the Movie:The Revenge of Belial
Ultraman Ace was one of the Ultraman who protected the Land of Light after the Darklops Zero were about to destroy it. Ultraman Zero The Movie: Super Deciding Fight! The Belial Galactic Empire
Seven noticed that his son had travelled to another Universe. With the appearance of the other Ultra Brothers the question is raised, if Zero's universe hopping was in any way related to the multiversal threat they had detected. A ship of unknown origin giving off a strong amount of minus energy was abducting monsters, dead or alive, even those in the Monster Graveyard. The Ultras declared they would watch for the threat but also noted they could only monitor a small amount of the countless other mulitverses at any time before the climatic battle against Hyper Zetton & Multiple Sphires created replicas of Antlar, King Pandon, Tyrant, Black King and Verokron. The Ultra Brothers: Ultraman, Seven, Jack, Ace and Leo transformed into their Ultra forms to help Ultraman Saga. The mighty brothers arrived in the field of battle, and each went to fight the monsters, with Ace going straight to his old nemesis Velokron. After a short battle, Ace used his signature move, the Metallium Ray, and finished off his old rival once and for all. Ultraman Saga
Dark Spark War
Prior to the Ultraman Ginga television series, Ultraman Ace participated in the Dark Spark War but this time he fought not only alongside with the Ultra Brothers but, with the other Ultras seen so far and their allies against the forces of Evil. Ace was shown fighting alongside his brother and his parents. While in the midst of battle, Dark Lugiel appeared and turn every Ultra alongside their allies, monsters and aliens into Spark Dolls. Ace was seen among his brothers, trying to protect Taro from the Dark Spark's curse. Just as the war about to end, an unknown warrior appear and faced Dark Lugiel but like the others he also turned into a Spark Doll but he was kept within his Ginga Spark and fell alongside other Spark Dolls. It is assumed that like all other Spark Dolls, Ace fell to Earth. At the end of the series he returned home with the other Spark Dolls after Lugiel's defeat.
Ultraman Ginga S
As mentioned by Taro, Ace was among the five senior members of Ultra Brothers that donated him their powers as a sign of support. Thanks to this, Taro changed himself into Strium Brace for Hikaru Raido/Ultraman Ginga to assume Strium Mode. Ace's power were seen used, among them is Metallium Ray against Yapool. It is presumed that his powers were returned back after Taro's job on Earth is done.
Ultra Fight Victory
Ultraman Ace was sent by Ultraman King to rescue Ginga from Ace Killer, who had the Ultra imprisoned, similar to the Ultra Brothers years ago. He seemed to have the upper hand in the battle, avoiding all of Ace Killer's attacks and finishing him off with the Ultra Guillotine. However, Ace was seemingly unable to overcome the Choju. Ace Killer proceeded to try and kill Ace, under the new title of Victory Killer, but Ultraman Victory came to defeat him. But While Victory was kept busy with the new and improved robot, Yapool summoned Lunaticks to kill Ginga. But soon Shou summoned Shepherdon and defeated both monsters.
After Ginga was freed, he and Ace's energy were restored by using some Victorium. Soon, the three Ultras joined the Leo brothers in Planet Guar to fight against Yapool and his Choju Army. Ace suggested that they merge to form Ginga Victory and they did. Ace defeated Verokron with the Vertical Ultra Guillotine while Ginga Victory managed to kill Yapool but was too late to stop his plan, having now revived Juda Spectre. Juda created Super Grand King Spectre to attack the Ultras and broke the former's fusion, forcing Victory to fight Juda alone while Hikaru/Ginga joined the Space Garrison to fight Grand King.
After Super Grand King Spectre launched some more energy blasts, Ginga launched a Ginga Thunderbolt at him to weaken him a bit so that the other Ultras can deal some more damage to him in close combat. When Victory used his powers in Knight Timbre mode to distort Juda's distortion to his own, the particles from that said dimension weakened Super Grand King Spectre enough to be left immobilized and was defeated by a combination of Ace's Metallium Ray, Leo and Astra's Ultra Double Flasher, and Ginga's Ginga Cross Shot while Victory defeats Juda once and for all with his Knight Victorium Break. With Juda dead, the stolen Victorium Core and Hikaru/Ginga and Shou/Victory returned to Earth, where Hikari congratulated them for their bravery before returning to space.