Haru is a white man raised by a Ninja clan in Japan, after he was found as a baby on a shipwreck. They believed he might be the "White Ninja" prophesied by their legends, a foreigner who would grow up to become their greatest member. However, Haru grows up to become both clumsy and clueless. Although disappointed in him, his clan still loves him like one of their own. In turn Haru idolizes Gobei (Robin Shou), his "older brother" and the best Ninja of the clan.
One night, while the rest of the Clan is away, their Dojo is visited by a beautiful woman named Sally (Nicolette Sheridan) who wants to hire a Ninja to spy on her businessman boyfriend, whom she suspects is involved in shady deals. Haru, taken in by her beauty, tells her he is a full Ninja (he hasn't actually graduated yet) and goes on the mission. It turns out that her lover is indeed a criminal, involved with the Yakuza in an international counterfeiting scheme- and a cold-blooded killer to boot. Obsessed with protecting Sally, he decides to go to Beverly Hills to find her. Unknown to him, Gobei is following him, and keeping him out of danger without his noticing.
In Beverly Hills, Haru meets Joey Washington (Rock) a hotel employee who, realizing that Haru is a ninja, begs him to be trained as one and helps him get around. Eventually Haru meets Sally again and, after several madcap events, finally confronts the criminals. When he finds out Gobei is in danger, he spontaneously develops full Ninja powers and rescues him and defeats the bad guys. In the end, Haru, now declared a full Ninja by his clan, decides to stay in Beverly Hills (with Sally) though he proves to still be an accidental threat to people around him.
This was Farley's last film to be released during his lifetime. His last starring role, Almost Heroes, was released posthumously a year later.
Beverly Hills Ninja contains examples of:
- Adaptational Heroism: Haru's ninja clan. The sensei is shocked when he hears reports of a ninja committing a murder. Odd for a group that developed as spies and assassins for hire. Their training techniques, temple layout, orange clothing, and aversion to murder seems to show they were not based off ninja, but instead Shaolin monks.
- Perhaps all ninjas had stop committing murders and have taken the peaceful way, and sensei was shocked to hear a ninja reverting to their old ways.
- Achievements in Ignorance: Haru has achieved at doing acts of competence when he tries to do what he can for mainly saving someone and helping everyone out in some instances (e.g when Sally was locked with a bomb in the room, some of his ideas didn't work out at first. At the very end where he manages to shoot a giant, metallic arrow through the wall and into a window, breaking through the wall Haru was trying to get into when it successfully led the bomb onto the villain's vehicle and manages to save Sally without knowing what would actually happen afterward).
- Astral Projection: Apparently a standard Ninja power, though Haru isn't very good at it.
- Acrofatic: Haru. And probably Chris Farley as well, since the credits label Farley as doing his own stunts.
- Back-to-Back Badasses: Haru and Gobei during the final fight.
- Big Bad: Martin Tanley.
- Big Brother Instinct: Well repaid by Haru, especially in the final battle. This quote sums it up best:"I may not be the best ninja, I may not be one with the universe, but I will tell you this: NO ONE MESSES WITH MY BROTHER!"
- Big "NO!":
- Whenever Haru enters and exits the Plane of Enlightenment.
- Whenever someone thinks Haru killed a person Tanley killed.
- Blindfolded Trip: Parodied. Haru is blindfolded when he is first taken to the Tanley's warehouse. Later, he blindfolds himself and tries to use his "ninja skills" to remember the route. He is completely clueless, of course. Luckily, Gobei knows the route well and takes the wheel without Haru knowing.
- The Chew Toy: Gobei. He endures so much punishment in this movie, you come to think that the world hates him.
- The Chosen Zero: Haru was said to be the Great White Ninja. He mostly sucks at being a ninja.
- Combat Pragmatist: In the final fight, while Nobu and the rest of Tanley's mooks fight Haru and Gobei with martial arts, Tanley himself fights Haru and Gobei using a machine gun.
- Comically Missing the Point: When Haru tells Sensei about Sally Jones, Sensei revealed that there's no one in the hotel she's supposedly staying in by that name. There's an Allison Page who fits "Sally"'s description. Haru suspects "Sally" gave the hotel a false name to hide her identity, while Sensei believes Allison most likely lied to Haru. But Haru believes she wouldn't lie to her, due to his 'ninja intuition'.Sensei: You do not even have normal intuition!
- Counterfeit Cash: The villains' plans revolve around stolen printing plates.
- Crouching Moron, Hidden Badass: Haru in the climactic fight. It's actually hinted at during the entire movie. During the training montage at the beginning, when Haru gets caught on the flypaper on the floor, notices he had already crossed two before getting stuck. He also shows at least some skill with the whip chain, an incredibly difficult-to-use weapon. His bird hat disguise also seems to genuinely impress his sensei.
- Deus ex Machina: Possibly justified if Haru really is the 'White Ninja'. Even he isn't sure afterwards.
- Disguised in Drag: Gobei at one point disguises himself as a woman to blend in and watch Haru without giving himself away.
- Distracted by the Sexy: Haru. First by Allison/Sally and second by the strippers. Sensei even accuses him of being led around by his "short sword".
- The Dragon: Nobu.
- Everybody Must Get Stoned: Haru tries to use a "truth dust" on a prisoner, who not only gets a hefty dose himself, but sneezes at the critical moment and ends up spraying the rest of the dust into Haru and Allison's faces.
- Genius Ditz: For all of Haru's stupidity and ineptitude of a ninja, he can show some quick wit to compensate and can come up with some unique plans aside from his ditziness (e.g Haru tricked the gunner when shooting a white bag thinking it was Haru's belly in order for him to run out of bullets, which was where he Took a Level in Badass).
- The Hero: Haru. The movie focuses on his development of becoming a ninja.
- Highly Visible Ninja: Played straight with Haru, who at one point goes so far as to charge into enemy territory wearing black with a sword on his back through the front gate in broad daylight. Averted with Gobei, who's very good at staying hidden or blending in.
- Karma Houdini: The honored elder at the Little Tokyo Temple. Lampshaded when one of the Kobudosai gang members, after the elder favors Tanley with the plates instead of the Kobudosai, says, "You won't get away with this!" the elder replies, "Yes, I will!" while the elder and Tanley's men point their guns at the Kobudosai.
- Let's Get Dangerous!: NO ONE MESSES WITH MY BROTHER!!!!
- Master of Disguise: Gobei does this to help Haru (and to an extent, Haru while doing this in a foolish manner).
- McNinja: Haru is caucasian, and raised in a ninja clan.
- Mighty Whitey: Parodied. Haru is the most incompetent ninja in the entire movie, although this says less about his race than it does his character.
- Mistaken for Badass: Almost the entire plot hinges on Haru being consistently mistaken for a badass ninja.
- Not What It Looks Like: Every scene where Haru is framed. Martin Tanley kills someone, the body lands near Haru, a witness or a cop sees it and thinks Haru did it.
- Paper-Thin Disguise: Haru's disguises frequently include fake mustaches.
- Pimp Duds: After Haru arrives in America, he goes to a costume shop to swap his ninja attire for something that will blend in better. He walks out wearing a pimp costume.
- Running Gag:
- Haru keeps leaving his shoes outside the hotel, where the janitor keeps taking them.
- Haru has a problem with the landing whenever he returns from the Plane of Enlightenment.
- Shamu Fu: Haru at one point beats up a thug with a pair of giant fish. It actually works pretty well.
- Took a Level in Badass: For most of the film Haru is hopelessly inept at being a ninja. But during the final battle he suddenly becomes a badass, surprising the hell out of Gobei.
- You Talkin' to Me?: In a Shout-Out to Taxi Driver: "Are you communicating with me?" Haru proceeds to attack the mirror.