Redbot a robot, Mick a shape-shifting alien and a young teen named Brody escape to Earth from an alien spaceship with a special artifact called the Ninja Nexus Prism. He and two new friends, Preston & Sarah, must unlock its secrets to defend it from the villainous champion Galvanax.
As Brody, Preston and Sarah return to Brody's childhood home in an attempt to find his lost family, Hayley and Calvin come across a strange alien named Mick.
Brody is accused of cheating on his first day of school after using his Datacom to find answers. Now, he must use his own abilities and leadership skills without it to lead the Rangers against another threat from Galvanax.
Preston is amazed when he discovers he's developed real magical abilities. Meanwhile, Galvanax hatches a plan with a new monster to steal the Ninja Power Stars.
While battling a new spider-like monster called Tangleweb, Calvin must learn to conquer his greatest fear to save the rangers and unlock a new power. The Green Elephant/Rumble Tusk Zord makes its debut.
Hayley and Redbot are separated from the other rangers, and Hayley learns that Redbot is capable of human emotion despite his robotic nature. Meanwhile, Madame Odious uses the Gold Power Star to torture a mysterious "stowaway" to become the gold power ranger and further her own plans.
Sarah tries to take part in several student activities, and creates the ability to clone herself, something which interests the wrong crowd. A new monster gains access to Sarah's tech and gives the cloning machine to Galvanax, who uses it to clone himself. Astro Zord rescues the mysterious stowaway who turns out to be the Gold Power Ranger on Warrior Dome.
The Ninja Steel Gold Ranger makes an appearance, and both Galvanax and the Rangers rush out to learn all they can about who it is. Brody finds himself as the new bodyguard for a country music star named Levi Weston. Levi later reveals himself as the gold ranger when his contractor is kidnapped by Ripcon. The Lion Fire Zord appears in a vision.
Levi is excited to be embarking on his world tour, but as mysterious earthquakes start shaking Summer Cove, he's presented with a tough decision.
When Summer Cove's sentimental "Ribbon Tree" is in danger of being cut down by Preston's wealthy dad Marcus Tien, Preston must learn to stand up to his father to save what's important. Meanwhile, Ripperat's brother Trapsaw tries to trap the Rangers but fails every time. Brody has another encounter with Ripcon. A man appears, claiming to be Brody's long lost brother Aiden.
Brody is eager to reunite with Aiden, though Mick, Levi and Hayley are suspicious of Aiden's motives. Later, a monster named Toxitea poisons Brody. Madame Odius demands the Rangers hand over their power stars in exchange for the antidote. Though Aiden urges them to agree to Odius' terms, Levi and Hayley create fake power stars made of chocolate and fool Odius into giving them the cure. The Rangers defeat Toxitea, though Odius escapes. At the end of the episode, Odius and Aiden are revealed to be working together.
On Odius's instructions, Aiden tricks Ripcon into helping him get the Ninja Steel. Ripcon attacks the city, distracting the Rangers except for Levi who's helping Mick create the new Ninja Fusion Star. With the Fusion Star, Brody beats Ripcon, forcing him to retreat. At the same time, Aiden breaks into the base and fights with Levi for the Ninja Steel. During the fight, Aiden is revealed to be a robot imposter. The other Rangers arrive just in time to save Levi and destroy the robot Aiden. Madame Odius frames Ripcon for both the failed robot plot and for hiding Levi on Galvanax's ship. Furious, Galvanax has Ripcon gigantified and forces him to fight the Rangers again. Although Ripcon initially overpowers the Rangers' Megazords, Brody uses the Ninja Fusion Star to combine their Megazords into the Ninja Fusion Zord. With their new Megazord, the Rangers finally destroy Ripcon. After the battle, Brody sings his father's song at a school talent show, triggering a flood of memories in Levi. It is revealed that Levi is Aiden, and that his childhood memories had earlier been stolen by Odius and placed in her robot. Levi/Aiden now remembers that, he went into hiding and assumed the identity of Levi Weston to protect himself from Galvanax. Reunited at last, Brody and Levi embrace. At the end of the episode, all the rangers sing the Family song.
Calvin finds himself increasingly distracted from his friends and Power Ranger duties when he spends all this time trying to impress his local hero.
A mysterious princess and her royal guard arrive on Earth to challenge the Ninja Steel Rangers.
The Ninja Steel Rangers band together with a new ally to try and defeat Galvanax's new champion but even their teamwork may not be enough.
Calvin and Hayley decide to run for office at school but are thrown into discord by a monster capable of recording their voices.
Redbot documents the adventures of the Power Rangers on his new blog, while a cat-like monster attempts to steal the Ninja Power Stars.
Preston must confront one of Galvanax's newest contestants after his magical spells backfire on his teammates.
While Sarah deals with issues at school, the Ninja Steel Rangers must overcome an invincible force field.
The final battle begins as Galvanax unleashes his devastating attack. But, Madame Odius betrays Galvanax. Aiden and Brody are reunited with their father.
A Halloween board game leads the Ninja Steel Rangers into Cosmo Royale's trap where they must confront monsters they have already beaten.
When Cleocatra freezes the Power Rangers in revenge for defeating Cat O'Clock, Sarah and Santa Claus must travel through time to save the day.