A young boy steps into an ancient relic shop, where he meets the enigmatic owner, Mr. Liu. Mr. Liu regales him with the captivating tale of Ninjago, a vibrant city within the Lego Universe often threatened by the malevolent Lord Garmadon, the father of Lloyd Garmadon and the ex-husband of Misako, known as Koko. The citizens of Ninjago harbor a deep disdain for Lloyd due to his lineage, which weighs heavily on him. Unbeknownst to them, Lloyd is part of a covert group of heroes: the ninja team comprising Nya, Zane, Jay, Cole, and Kai, all guided by their esteemed master, Wu, who continuously battles against Garmadon and his nefarious plans with an array of mechs.
On the eve of Lloyd's birthday, Garmadon launches another assault on Ninjago, only to be thwarted yet again. In his fury, he dismisses nine generals of his Shark Army for their incompetence in aiding him. Garmadon then devises a grand scheme to seize control of Ninjago, orchestrating the construction of a massive mech that withstands all weaponry. Simultaneously, Lloyd and his allies are reunited with Master Wu, who has returned from a lengthy journey. Wu tells them that true ninjas do not rely solely on mechs, which confounds Lloyd as he learns that his elemental power is linked to the color green. Wu encourages Lloyd to channel his intellect rather than succumb to anger when confronting Garmadon and mentions an Ultimate Weapon, instilling hope in Lloyd to triumph over his father, despite the weapon's prohibition.
As Garmadon attacks with his formidable mech, he quickly overpowers Lloyd. As he claims dominion over Ninjago, Lloyd reveals the Ultimate Weapon to combat Garmadon, inadvertently attracting a colossal cat named Meowthra with a laser beam. The chaos that ensues allows Garmadon to manipulate the cat into wreaking havoc upon the city, subsequently leading to the destruction of several mechs. Amidst this turmoil, Lloyd confronts Garmadon, declaring that he wishes he were not his father, further confusing Garmadon.
Undeterred by Lloyd's use of the weapon, Wu and the other ninjas prompt Lloyd to seek an even more powerful weapon—the Ultimate, Ultimate Weapon—which requires traversing treacherous locales: the Forest of Dangers, the Canyon of Death, and the Temple of Fragile Foundations. Garmadon, having eavesdropped, stealthily follows them. Tensions escalate when they are ambushed by the Shark Army, who are out for vengeance. After a harrowing fight, the ninjas find themselves retreating, leaving Lloyd and Garmadon vulnerable to capture. Just as they face being tossed into a counterfeit volcano, their allies spring into action, employing stealth tactics to rescue them from the Shark Army's clutches. Remarkably, this ordeal fosters a connection between Lloyd and Garmadon.
Upon crashing into the Temple of Fragile Foundations, Garmadon, revealing his deep regrets, reminisces that Koko was also a warrior in her time. Despite a moment of bonding, Garmadon surrenders to the temptation of power and snatches the Ultimate Ultimate Weapon for himself, inviting Lloyd to join him in his sinister quest. However, Lloyd rejects this offer, igniting Garmadon's fury and resulting in them being imprisoned in the crumbling temple. In a moment of clarity, Lloyd comprehends that inner peace is fundamental to unlocking their powers, allowing them to wield their elemental abilities and escape.
Just as they plummet from the temple's edge, Master Wu arrives just in time aboard the ship, Destiny's Bounty, whisking them towards Ninjago. Garmadon's attempts to dominate Meowthra backfire, leading the creature to consume him. As the final confrontation unfolds, Lloyd proclaims his identity as the Green Ninja and realizes that green embodies life and unity, leading to a reconciliation with Meowthra and ultimately with Garmadon. Lloyd expresses forgiveness towards Garmadon, who, overwhelmed by emotion, ignites a change within himself. The resolution sees Garmadon joining Lloyd and Koko, while Meowthra becomes the beloved mascot of Ninjago. Lloyd emerges as a celebrated hero, and the boy listening to Mr. Liu learns that he will soon embark on his own journey of becoming a ninja.
> "It’s your destiny to be the hero!"
