Hiroto Sutou was someone that didn't have a lot of friends growing up. He and his sister Miu were all but sequestered within their family's estate, only venturing out to pick up various skills. While the two of them could be called exceedingly skilled, it came at the cost of the two being deprived of most real relationships. That was, until they joined up with the Go-Ongers in their quest to defeat the Gaiark and their plans to pollute the Earth. While the two had returned to their rich lifestyle, at their parents' insistence, they had kept in contact with both their new friends in the Go-Ongers and their partner Engines, Toripter, Jetras and Jum-Bowhale. It was during the wait for one such of these reunions that Hiroto found himself surrounded by a golden light, vanishing from his house. It was as he vanished that his sister Miu came into the room, confused as to where he had gone. "Ani?", she asked, confused. "Where did you go?"

Hiroto awoke to find himself being overseen by a cloaked figure. "Wake up, Go-On Gold.", the figure stated. "Welcome to your new world of residence, for the foreseeable future."

"Another world, huh?", Hiroto commented. "What do you want with me?"

"You and 4 others are part of an experiment I am conducting.", the figure said in response. "All you need to do is fight against some enemies that will be in your way, both old and new. While at the same time, I want you to develop something for me based on some plans I will send you."

"Wait a moment.", Hiroto put his hand out. "You mentioned there were others beside me. How can I possibly find them?"

The cloaked figure thought for a moment, but then he spoke again. "Go to this address.", he handed Hiroto a sheet of paper with an address written on it. "There you will find what you need to begin the task and gather all the subjects together. And I assure you that once the experiment has concluded, then you will be returned to the world you left, at the exact point you left it. And for the duration of your stay here, your ageing process will be suspended." With all of that said, the nodded figure turned around and faded away.

Hiroto tried to reach out for the man, only to find he was gone. Checking the sheet of paper he was given, he realised the address was in Shinjuku, the commercial area of Tokyo. "So, let's see where this leads me." He set off, looking to find his new home.

While passing through Tsuchiura City in Ibaraki, Hiroto's uncanny sense that something dangerous was nearby began to act up, which alerted him to head off course to his left. Sure enough, he saw a group of familiar cybernetic opponents tearing up the streets, and scaring the populace. "Ugutz!", Hiroto stated. "So that's what he meant when he mentioned old enemies." He ran forward, using his martial arts training to fight off the robots. "Where there's Ugutz, there's usually a BankiJuu accompanying them."

Sure enough, a green robot-like creature appeared, with a grill forming much of the head, a pair of red eyes prominently featured. It's arms were claws with a groove in each of them. "Oh, looks like I've found an interesting partner.", the monster growled.

"So, you're the latest one, are you?", Hiroto asked. "Seems like you won't be much trouble, right Miu?" He paused, waiting for a response from his sister. But then he remembered. "Right, I'm doing this one alone."

"Oh, so there's only one of you Go-On Wings this time.", the BankiJuu noted. "Well let's just see how you do on your own against me, Dump Banki!" He then retracted half of his claws, before linking his two arms together into a tray similar to the one on a dump truck. "Dump Shot!" A large ball of garbage was generated in the centre of the tray, launching itself at Hiroto, and blowing him backwards as the garbage was scattered around the street. "This is only the start of my plan.", he announced. "I will turn the entirety of Tokyo into a Gaiark paradise." And with that, he leapt off, leaving Hiroto to pull himself up.

"Looks like I'm going to have Gaiark remnants to contend with.", Hiroto noted. "But first, I should think about searching out the other test subjects and enlisting them."

And so, he continued to the address he was given, ending up in a warehouse, containing a large pink circle, with scaffolding for maintenance surrounding it. But he ignored that, going over to a computer console, where he found three familiar Engine Casts on the top. "Toripter! Jetras! And Instructor Bowhale!" Hiroto looked around for their Engine Souls, finding them in the briefcase for their Casts, which was next to a charging device for the Engine Souls and a projector for the Engines in their soul form.

His first instinct was to place them in the former of the two, before inspecting the console. It displayed a map, depicting 5 blips across a map of Japan. While one of the other 4 was in Izu-Ōshima, which was relatively nearby, the three remaining were out in Kyoto City. But there was an option on the computer that would allow him to teleport something one-way to their location. So, taking out some of his family's personal envelopes and some paper, he wrote four identical messages, all addressed to the other 4, whose names - Kaito Kumon, Yakumo Kato, Shinya Hiraga and Momo Maruo - were written on their blips, before placing them into the transporter, setting the coordinates to take them to the nearest area to everyone's current location where it wouldn't arouse much suspicion. Now, all he could do was wait.

"Hey, Aniki." Hiroto was interrupted as he saw Toripter's Soul leap out of the charger and into the projector. "How did we get here?", Toripter asked. "And where's Miu-neesan?

"For your second question, I don't know for sure.", Hiroto answered. "As for the first, someone brought us here. Brought us here to fight. And to build this." He looked over the plans provided briefly, spotting the English word "Genesis". "When you're recharged, I'll need you to do something for me, aibou."

And so, when Toripter was charged up and sent on his way, Hiroto spoke with the other two Engines, who were also fully charged. "So, you think if we work with whoever these guys are, we can get home?", Jetras asked. "I have my doubts."

"Boe!", Jum-Bowhale said in response. "Remember how you once thought the same about the Go-Ongers? And we ended up good friends in the end."

"Maybe.", Hiroto interjected. "But they won me over through how endearing their stupidity was. I doubt whoever we're bringing in will be the same."

Soon enough, Toripter returned, with his three passengers disembarking. Hiroto registered a man in a red and black jacket, a man in a blue suit with a long jacket and a man in a black sweatshirt with jeans. Neither of them seemed particularly impressed. "For someone who owned his own custom helicopter and envelopes, I was expecting a mansion.", the third man commented. "Not an old abandoned factory."

"I'm pretty sure it's a warehouse.", the first of the three spoke back. "But you're right. This place looks like no-one's been in here for years."

"No-one has.", Hiroto said as he approached the three. "I'd only just moved in here myself when I got in touch with you three."

The man in the blue suit flexed his sword in his hand. "So, you're the one who sent those letters to us, I presume."

"You would presume correctly.", Hiroto said as Toripter shrunk down and landed him his palm, the Engine Soul ejecting. "Now then, I'll fill you in on the details I've managed to find out while I've been here."

And so Hiroto explained the basic details of both his time in this world, and most of what the mysterious figure had told him. He left out the details concerning the mysterious project called "Genesis". He thought that if they knew about that, they'd be less willing to fight and that may result in them never going home. Hiroto hoped that if he completed the device, then the one who brought everyone here would send them back. Then he allowed the other three to share their experiences of being in this place. It seemed that as the nodded figure had told him, each of them had an old enemy in this world. He assumed the fifth subject would also have an enemy in this world to battle. After the explanations were over, Kaito was the first to say something. "So, we have to fight off the revived evils threatening this world in order to get back to our own. That sounds simple enough."

"You say that like you expect it to be a game.", Shinya reprimanded him. "While it might not be our world, there are still people in danger."

"If they choose to put themselves in danger, then that's on them.", Kaito stated. "The weak endanger themselves, while the strong will be able to escape the danger."

"The strong are also tasked with protecting the weak.", Hiroto pointed out. "But sadly, very few actually think to do so. We few are the ones who have been given the power to protect the weak. And it's our mission to use it properly." As he said this, he felt something appear in his hand. It was his Wing Trigger along with the Change Soul to use it.

He then took out Toripter's Soul and inserted it into the device, causing the usual hologram to be generated. "Hey, hey, Aniki! Do you know what this means? You can change again."

"That's right.", Hiroto nodded, before sensing something. "So that Gaiark is back again."

"Well then, let's go.", Yakumo insisted. "With the four of us, it'll be easy."

Elsewhere, the trio of mismatched villains, Demushu, Ariake and Dr. Zora, had pursued their enemies to Tokyo, in disguise as a group of regular tourists. They took note of the news. "It seems that another monster has appeared in this city.", Dr. Zora noticed. "Is he one of yours, Ariake?"

"Eh? Certainly not.", was Ariake's blunt response. "I would never associate with someone as uncouth as that ruffian. Unless I needed his protection, like my arrangement with Demushu here."

"I like his style.", Demushu commented. "I think I'll go and help him destroy this city."

Dr. Zora was instantly opposed to this. "No. We need to keep a low profile until we can find a base of operations."

"Allow me to handle that." All of them turned around to search for the source of the low, gravelly voice. But they couldn't find one. "Your violent friend can go and fight if he wants to. My servant could do with all of the help he needs."

Demushu laughed. "I don't know who you are, but you're the best boss I've had since I came to this dump." He reassumed his Overlord form and walked off.

The ominous voice then continued. "Now as for you two, I will direct you to my location. Then we can commence with our plans to take this world."

Ariake was now slightly scared. "Who is this?", she asked. "Come out!"

"If I had to guess.", Dr. Zora answered. "I'd say he's the latest member of our new gang."

Elsewhere in the city, Dump Banki was using his powers to toss garbage throughout the street. "The noxious fumes this produces will quell the human's will to resist. When we create our Gaiark paradise, they will become more Ugutz."

"I don't think so." Hiroto came running, accompanied by Kaito, Yakumo and Shinya.

"Ah, so the loser came back for more punishment.", Dump Banki said mockingly. "And he brought along some more suckers. You must be a glutton for punishment." He then summoned up a group of Ugutz.

"Oh I'm not the same as I used to be.", Hiroto responded as he pulled out his Wing Trigger. "I've levelled up." He then took out his Change Soul, inserting it into the device. "Change Soul, Set!" He pressed the button on the back of the Trigger and moved his right arm backwards. "Let's Go-On!" His suit was generated onto his body, before his helmet appeared above his head. He grabbed it, putting it on. "'Met on!"

The other three then joined him in transforming. "Henshin!"

"Shuriken Henge!"

"Souchaku!"

Soon, all 4 of them stood transformed in front of the enemy forces. "Break the Limit, Go-On Gold!"

"Armoured Rider Baron!"

"The Roaring Cloud, AoNinger!"

"Justiriser, Gant! On stage!"

The four then ran into battle, suing their weapons to easily cut through the Ugutz, with Yakumo going for a new weapon. "Karakuri Hengen: Tsume!" He slashed at a few of the Ugutz with this.

Hiroto likewise made some progress using his own weapon. "Rocket Dagger!" He then flicked the switch numbered "3". Mission 3! "Lightning Dagger!" He swung the weapon, zapping all of the mechanical footsoldiers with an electrical energy wave.

With the Ugutz dealt with, the group thus moved onto Dump Banki. "Now hold on a minute, guys.", the BankiJuu pleaded. "You can't honestly believe 4 against 1 is any way fair."

"In that case, allow me to even it up." A set of energy projectiles flew through the air, knocking all of the heroes down. The source of the voice stepped forward. "Yo, ape. It's been a while."

"Demushu!", Kaito, the target of the taunt, growled. "So, you're here as well."

The other three pulled themselves up. "Friend of yours?", Hiroto asked.

"More of an enemy, really.", was the response from Kaito. "I advise caution with this guy."

Yakumo then placed his NinShuriken on his Karakuri Hengen The Karakuri! "In that case, we'll take him out right now.", he called out as he thrust the weapon forward, sending a blue energy claw towards Demushu. Tsume Karakuri Retsu!

But Demushu took this shot straight to his chest, surviving with barely a scratch. "My body has evolved long past the point where that could phase me." He then ran forward and locked one of his sword's blades with Yakumo. "But let's see how you and your friends appreciate our onslaught." He clicked his fingers, opening a set of cracks and unleashing three mushroom-like creatures onto the fight, who then moved over to face Kaito, Shinya and Hiroto.

Shinya took a few shots at his opponent, buffeting it. "What are these things? They're pretty tough."

"These are Inves. Very basic and weak, but still an Inves.", Kaito answered as he took out the other Lockseed he had received recently. "Let's see what this one can do." He clicked it open. Kiva! He then placed it on his Sengoku Driver, locking it in. Lock On! After a few seconds, he used the knife to open it, as a bat-like head formed out of crystal and shattered into shape, before falling onto Baron's head and opening up. Come On! Kiva Arms! King of Vampire!

Everyone stopped to look at this new form. "That looks… familiar.", Hiroto noted.

Kaito then ran towards Dump Banki, who prepared his attack. "Dump Shot!" But Kaito backhanded this, before initiating his Sparking function. Come On! Garulu, Bashaa, Dogga! A blue wolf man, a green fish-like creature and a large, purple hulking beast appeared, accompanied by a dog whistle, a trumpet and a horn respectively, with all of them attacking the BankiJuu. The wolf man scratched with his claws, the fish creature launched a bubble of water and the purple hulk launched a powerful punch, all of them knocking Dump Banki back. All three of them then transformed into weapons, a scimitar, a flintlock and a hammer respectively, which flew into the arms of the other three.

"I don't know what these things are.", Yakumo commented as he observed his new sword. "But I can make use of these." All three then turned to face Demushu and his three Inves. Yakumo was the first to attack, with the sky turning to a full moonlit night. "Garulu Howling Slash!" The sword extended as he brought it down.

The moon then changed to a half moon as Shinya fired the gun. "Bashaa Aqua Tornado!" A large tornado appeared, through which a shot was fired.

Hiroto then wielded the hammer, as the moon changed to a moon surrounded by thunderclouds. "Dogga Thunder Slap!" An eye on the hammer opened, before Hiroto brought the weapon down.

"Protect me.", Demushu yelled as he forced all three of his Inves in front of the blows, making them take the full blow while he was completely shielded. Two of them were destroyed, while one of them managed to stagger out. "So, you were strong enough to withstand that, huh?", the Overlord noted. He then took out a Helheim fruit, feeding it to the Inves. "I suppose you deserve a reward. I'll let you feed on these apes." And then, he turned around and moved away at what looked like super speed.

As it consumed the Helheim fruit, the Inves transformed from an elementary state to a more humanoid state, blue with several feelers sticking out of its head and arms, with armour seemingly made from leaves. As it charged forward, hunting for prey, it was faced down by Kaito, who initiated the Squash function on his Driver. Come On! Wake Up! The moon in the sky changed to a half moon, as Kaito swung himself so he was upside down, before hitting the monster with his shin, knocking it back.

Across the street, Dump Banki was on the receiving end of attacks from the other three, with Hiroto going first. "Burning Dagger!" Mission 1!

As this hit Dump Banki, Yakumo went next. Kaen no Jutsu! "Shuriken Ninpo: Kaen Abare Giri!" Mera Mera Ja! Yakumo surrounded his sword with fire, before slashing at Dump Banki.

Finally, Shinya aimed his weapon and fired. "Versus Cannon!"

The shot launch Dump Banki over to where the Inves was struggling to clamber up. "I said that you were too powerful taking us on together.", he commented.

"Attention, Wing Booster!" Hiroto set his Rocket Dagger to Mission 6, before plugging it into his Wing Trigger. "Toripter Soul, set!"

As he inserted the Engine's Soul, Toripter commented. "Finish 'em off, Aniki!" 3, 2, 1, 0!

"Go-On!" Hiroto fired a shot in the shape of Toripter's full body, that crashed into the two monsters, causing them to collapse and explode.

"Looks like my plans to create a giant scrap heap ended up on the scrap heap.", were Dump Banki's last words before his demise.

With their foes vanquished, everyone undid their transformations. "Well that was a job well done, if I do say so myself.", Hiroto noted.

Yakumo took umbrage at this statement. "Hey, you were only able to defeat that robot with our help."

"Please, you just copied what I was doing.", Hiroto chided him. "All those ninja skills and you have to steal my style?"

"You still needed my help with that Inves.", Kaito added. "If it wasn't for my new power, you would've had a harder time destroying it than the one shot you got in with your own weapon. I was the real deciding factor in our victory."

"Look at yourselves, trying to claim the credit for yourselves.", Shinya chided. "If I hadn't fired my Cannon, you'd have had to destroy both of those things separately."

As the 4 continued arguing, a fifth figure observed them from within the bushes, sighing. "If I have to work with these people to get home, then I'm in for a wild ride."

Elsewhere, Dr. Zora and Ariake ended up at an abandoned factory. "So, this is where our other ally wants to make our base.", Dr. Zora noted. "This isn't bad for a hideout."

"Of course." The same voice from before bellowed, but this time, both women could see the source. A bulky black robot with three red eyes and a golden beard. "With the industrial equipment in this factory, you can create all the Cyber Knights and Zargoal you desire. While I can manufacture new and better BankiJuu, not like that failure who just got defeated. He doesn't deserve to be revived as a giant."

"That's all well and good.", Ariake commented. "But given that you've offered Zora-chan a large workshop and Demushu-kun a few chances to kill those nuisances, what can you offer me, Big Black Body-kun?"

"I am Gaiark's Prime Minister Yogosmacritein.", the figure announced. "And don't worry, We've set you up with a personal spa so that you can get your regular beauty treatments. You and your servants can spend as much time in there as you deem necessary."

Dr. Zora noticed his choice of words. "You said 'we'. Perhaps you can explain that."

"I can do that better.", a new voice, this one female, answered. Everyone turned around to see a mostly pink robot, wielding a bow. "I'll also be making use of this factory, creating an army to rebuild my Bulpie's Baranoia Empire bigger and better than ever, to take Earth in his name."

"Ladies, I'd like to introduce Empress Malthiua of the Machine Empire Baranoia.", Yogoshimacritein stated. "The final member of our coalition. A coalition that will destroy its enemies in this world utterly."