The Ninja Steel Rangers were on a flight to Japan, while also passing through a dimensional barrier so they could meet Kuroninja, the Ninningers, and anyone else on Earth-1. This was also how the Ninningers made it to Earth-2 so Anti-Kuroninja could get them to fight each other. However, it was a being from Earth-0 who decided who would travel between worlds.
Anyway, the Ninja Steel Rangers were going to Japan, but they still needed to attend school. Sarah, the pink Ninja Steel Ranger, had improved her cloning device, so duplicates of the Ninja Steel Rangers would attend classes and protect the Earth (Power Rangers Earth/Earth-2) from Galaxy Warriors contestants. What Galaxy Warriors didn't realize was that they were fighting fake Ninja Steel Rangers who didn't have the Ninja Power Stars.
There weren't that many Galaxy Warriors contestants, however. Akuroninja had taken over the show, and offered a bonus challenge of getting 3 powerful globe-shaped devices. No one was participating, and then Akuroninja realized that the globes were in Earth-9. Akuroninja then summoned some help from his home dimension, Earth-4. These were soldiers who looked like power rangers and sentai rangers, but on Earth-4, they were Enforcers, soldiers who served the leader of Earth-4. Akuroninja was the leader of Earth-4. He sent the Enforcers to go to Earth-9, and opened a portal for them.
Galvanax needed to get Akuroninja removed from the Warrior Dome, but he didn't know who could defeat him. That was when Galvanax remembered when the Ninja Steel Rangers fought the Ninningers, and it was organized by Anti-Kuroninja. Galvanax decided to find Anti-Kuroninja.
Meanwhile, on Cyber Island, Anti-Kuroninja was in his room with Cyber Kuroninja, who was distracted by the numerous Shironinger-related stuff everywhere. Anti-Kuroninja had been watching the city and noticed that Kuroninja or anything related to him wasn't seen during the past few days, even if the Ninningers were there. Cyber Kuroninja told Anti-Kuroninja that this was a good opportunity to do something. Anti-Kuroninja said that this was a good opportunity indeed, while staring at Shironinger's helmet. Cyber Kuroninja knew what Anti-Kuroninja was doing and thought that this was a waste of time, but he still went with Anti-Kuroninja.
Anti-Kuroninja knew how to lure the Ninningers to his location. What he did was throw a Cyber Shuriken on the floor, which would release the same element used by Yokai to trick the Ninningers into arriving, thinking that there was a Yokai. Anti-Kuroninja decided to wait.
That was when a small spaceship appeared. Galvanax had made his appearance. Anti-Kuroninja didn't recognize Galvanax at first, but then remembered when he wanted the Midoninger Shuriken. He then remembered who Galvanax was. That was when the Ninningers appeared.
Akaninger saw Cyber Kuroninja and remembered how Kuroninja wanted something from Cyber Kuroninja. However, the Ninja Steel Rangers appeared and saw Galvanax.
"It's the Ninningers...and they're working with Galvanax," the Red Ranger said.
"That guy from the future was right," the blue ranger said, seeing Cyber Kuroninja and Anti-Kuroninja, recognizing them from Akuroninja's fake message from the future.
StarNinger noticed that the Ninja Steel Rangers mistook the Ninningers for working with Galvanax, and they seemed to be talking about a message from the future. He told Midoninger to search for Kuroninja, wherever he was, before preparing for a second fight between the Ninja Steel Rangers and the Ninningers.