3 Ninjas Kick Back - Plot

Plot

Planning to go away to Japan with Grandpa is not as easy as Samuel "Rocky" Douglas (Sean Fox), Jeffrey "Colt" Douglas (Max Elliott Slade), and Michael "Tum Tum" Douglas (J. Evan Bonifant) had hoped. After expressing their different views on how they want to spend their vacation, Mori (Victor Wong) becomes concerned that his grandchildren are growing apart, both from himself and from each other. Tum-Tum seems to be the only one interested in traveling to Japan, and even then only hopes to go and watch Sumo wrestlers due to the amount of food they are able to consume every day, while Mori intends to return a dagger to the Grand Master at a martial arts tournament that he had won 50 years prior from a boy named Koga (Sab Shimono).

Meanwhile, in Japan, a figure dressed in all black ninja attire sneaks into a museum. After defeating several guards, the mysterious figure makes off with a valuable sword and escapes via a hang glider into the night. In the U.S., a baseball game determines that the three ninjas are experiencing the pains of growing up. Colt has become impatient and very short-tempered, starting fights with several of the bigger bullies on the opposing team. Rocky is very easily distracted by the school hottie Lisa D. Marino (Maital Sabban), and Tum-Tum's self-obsession with food breaks several plays, though not before a very flatulent batter breaks wind, causing the youngest of the Douglases to pass out. A huge in-game fight causes the umpire to call off the championship game, delaying it a week, driving a nail into Mori's plans to take his grandchildren to Japan as they wish to remain and finish the game. En route to the airport, a sticker falls off Tum-Tum's bag, and Sam picks up the wrong one, thinking it is Mori's bag. After Mori departs, the kids discover three intruders at Mori's house and fend off the property. Little do they realize that the trio is led by Koga's platinum rocker haired nephew, Glam (Dustin Nguyen) and his friends who were sent to steal the dagger from Mori.

After a call from Mori that a fender bender put him into a hospital, the boys discover that Tum-Tum has Mori's bag with the dagger inside. They decide to, without their parents' knowledge or permission, use a recording of their conversation with Mori to authorize plane tickets to Japan. Upon their arrival, they reveal to Mori that they have the dagger, and he instructs them to deliver it to the Grand Master. Disguised as nurses, Glam and his friends record their conversation and deliver it to Koga, who punishes them for not once but three times failing to deliver the dagger, before creating a plan to get it back. The boys attend the tournament, and Colt, dressed as a participant is not only painfully defeated, but by a girl named Miyo (Caroline Junko King), a baseball enthusiast as well, but with no skill in the sport whatsoever. She offers the boys a place to stay and in return for training in baseball, she will teach them some of her martial arts skill. Rocky develops an attraction for Miyo, and puts aside his shame for having to use reading glasses as she has a pair of her own. The Grand Master pays a visit, but the boys and Miyo are suspicious when he speaks English to them, as he had previously been unable to and Miyo had to translate for him. As well as wearing a pair of black shoes whereas before he was barefoot. When Miyo discovers the deception, she warns the boys who find out that it is in fact Koga in disguise. He sends his henchmen after the children who soundly defeat most of the troop before they are themselves captured. At the same time, Mori is taken from the hospital after a botched attempt from Glam and his friends to secure him themselves. They are all reunited, and Koga threatens the boys' lives unless Mori relinquishes his dagger. Mori agrees, and they travel to a hidden cave, which the sword and the dagger are keys to unlock the doorway to lead them to a legendary Cave of Gold.

After escaping their captivity, Rocky, Colt, Tum-Tum and Miyo take hang gliders to catch up with Mori and Koga, arriving in the cave they battle and elude each of Koga's men. Mori and Koga discover the cave of Gold, and as Koga readies to shoot Mori, the children arrive, prompting Koga to instead try to kill all of them. Remembering training that Mori taught him about patience, Colt manages to throw a small ninja ball into the barrel of the gun, causing it to back-fire. The explosion causes the cave to begin to collapse and all six of them manage to escape the cave. After realizing what the greed had done to him, Koga throws the sword into the cave, closing the door forever. After Koga apologizes to Mori and the children for his behavior, Mori presents Miyo, the new champion of the martial arts tournament with the dagger as he was presented it 50 years ago. They then realize that they can make it back to the United States before the championship game. When they return, they overcome their flaws. Tum-Tum stopping two runs from scoring, despite the bean kids' flatulence. Rocky throws a pitch, which is hit into the outfield, though a player who had been short-notice registered to the roster catches the ball, revealing that its Miyo. And using his training, Colt is able to hit a bases-loaded home run. After the game is won and over, the bullies attempt to confront Miyo in the parking lot, and despite Tum-Tum's warnings that "She's just a girl!" they try to fight her, only to be beaten up.