The three ninjas are back, but it soon becomes evident that they are growing up and growing apart; their grandfather planned a trip to Japan for the four of them, but after a mysterious car accident the three ninjas must travel to Japan alone to take on a mysterious adversary. Rocky, Colt, and Tum-Tum are the three ninjas. In this sequel their grandfather Mr. Mori has planned a trip for the four of them to visit Japan, so that they can push their martial arts skills even further and so that Mr. Mori can return a dagger. But a number of setbacks along the way make it evident that the three ninjas are growing up, and their interests are diverging; the issue's the three ninja's face include Tum-Tum's constant appetite, Colt's inability to control his anger, and Rocky's burgeoning interests in the opposite sex. The boys' issues come to a head at a baseball game where the bullies from a rival team somehow manage to further the rift between the three.
Mr. Mori notices his grandsons' shifting foci and decides to go to Japan on his own so that he can return the dagger, that he won during a tournament 50 years prior, to a martial arts master. The loser of the tournament from 50 years ago, Koga, has his nephew Glam and his three friends attempt to steal the dagger from Mr. Mori. The three bungling wannabes follow Mr. Mori to Japan and manage to crash the taxi Mr. Mori is riding in, giving the three ninjas' grandfather some minor injuries, and a stay at the local hospital. After informing his young proteges of his situation, Rocky decides that the three of them must go to Japan and return the dagger for their grandfather. The boys use a recording of their grandfather's voice to book their tickets, and they gather up all of the money lying around the house and make their way to the airport, and from there they will travel to Japan.
Once the boys arrive, they attend a tournament in hopes of returning the dagger. Along the way the three watch a mysterious ninja in white taking out all of the other competitors, so Colt decides he must prove himself against this talented ninja. Colt loses the fight and the three brothers discover that the mysterious ninja is a young girl named Miyo. Miyo helps the three ninjas talk to the grand master so that they can return the dagger,but the Grand-master decides it would be more honorable for Mr. Mori to return it, and Rocky takes a liking to Miko. The four of them find a common ground baseball and ninjutsu; Miko loves baseball but she isn't so good at it . And the other brothers decide to help Miko become a better baseball player, and she will help them become better ninjas.
Mr. Koga disguises himself as the Grand-master, and kidnaps the three ninjas and Miyo. After that Glam and company sneak into the hospital and attempt to kidnap Mr. Mori, but the three of them are dispatched by the elderly master. But after his quick escape Mr. Mori is taken away by a mystery assailant and is taken captive right along with his grandsons. Koga tells Mori to give up the dagger and the location of a secret stash of gold and he will release all of them. With the dagger and the sword in hand Koga reveals to Mori his plan to find the fabled cave of gold. Together the dagger and the sword act as keys to a hidden passage way full of riches. But like any good grandchildren the three ninjas aren't far behind the grand father. After a long drawn out battle Koga attempts to shoot the three ninjas, but his bullet is blocked by a ball bearing that Colt throws into the chamber of the gun. After the gun backfires it causes a cave-in a Koga and the three ninjas put their differences aside to escape.
Once the three ninja's return to America they make it to their championship game against their rivals. But unbeknonst to the three Miyo joined their team. After defeating their rivals, Miyo teaches the bullies a lesson they won't forget: don't mess with the four ninjas.
Best part of story, including ending:
The first film was okay for kids, but this one just seems to attempt to cash in on the franchises name. The action is flimsy at best the acting is mediocre and the story is trite in that the trip to Japan doesn't seem that necessary. Mr. Mori would injuries weren't that severe and he could have easily sent for the dagger via mail and returned it himself and not put his grandchildren in mortal danger.
Best scene in story:
When Miyo beats the main bully at the end of the film. The reason is she shows all of the guys in the film how tough she is.
Opinion about the main character:
The three ninjas are pretty terrible, it just doesn't seem like they care to much about nijutsu or baseball even after their long journey. And their jokes are pretty terrible too.