Galvanax, the champion of an intergalactic reality competition show called Galaxy Warriors was in search of the powerful Ninja Nexus Star. The star traveled to Earth and found the world's greatest Ninja Dane Romero. Dane fought Galvanax and protected his sons Brody and Aiden. Dane split the star in pieces and it became the Ninja Nexus Prism and six Power Stars. Dane became the Red Ninja Steel Ranger and fought Galvanax. Unfortunately, Dane lost and disappeared in a blast. The Power Stars became stuck in the prism. Ripcon kidnapped Brody and Aiden went into hiding with the Ninja Steel. Brody became prisoner on Galvanax's ship but befriended alien Mick and Redbot. Ten years later, they escaped with the Prism. Monster contestants went after them but Brody managed to befriend teenaged inventor Sarah and amateur magician Preston and they earned their Power Stars. The three became Power Rangers and were soon joined by Hayley and Calvin. The five vowed to protect the Power Stars and fight Galavanax's forces.
Brody discovered his father hid Ninja Steel in a trophy he had at the school. Mick became the replacement shop teacher and they made a section of the classroom into a hidden base for the Rangers. They make stars from the Ninja Steel, throw it into the prism and make them into Ninja Stars to activate zords, weapons, cycles and other arsenal. Cosmo Royale, the host of Galaxy Warriors would send send down one or two monsters contestants to fight the Rangers and the flying Spy Cams would record the fights. Madame Odius had a heroic young captive in secret who turned out to be the Gold Ranger and escaped in the Astro Zord. Soon the Gold Ranger would fight evil but run off as soon as the Rangers came into the scene. They soon discover it is country star Levi Weston. Very soon after, Brody's missing brother Aiden appears. Aiden seems mysterious, eager to fight and wanting to see the secret base. Levi finds him trying to steal Ninja Steel, fights him and discovers he is a robot.
After Aiden is destroyed and listening to a song Brody's dad used to sing, Levi's memories returned. Levi and Brody realized Levi was actually his brother Aiden. Princess Vera from the Lion Galaxy and her bodyguard Drillion came to Galaxy Warriors. Vera wanted to show she was brave and strong but realized the Rangers were the good guys thanks to Sarah. She turned against Drillion and let the Rangers use the Lion Armor and the Lion Fire Megazord. Brody was able to use the armor to become the Lion Fire Red Ranger.
Later, Monty and Victor create a magnet that catches Galvanax's attention and he steals it. Galvanax uses the magnet to take all the Ninja Stars and the Rangers' Power Stars. He kidnaps the Rangers but they manage to escape. Brody fights Galvanax much like his father did and disappears. He returns with Mick, also as a Red Ranger. They fight Galvanax. Dane comes out of the Prism as a Red Ranger and reveals the Prism was healing him and kept his spirit alive. The eight Rangers defeat Galvanax as his ship was shot down and collapsed. Madame Odius seemed to survived.