Trama

New circumstances forces Lilo and her alien friends to part ways while Gantu and Dr. Van Hamsterviel create the Stitch clone, Leroy, in order to capture all of the experiments and take over the galaxy.

After finding a home for all of the experiments, Lilo and the team must come together to fight against an evil male doctor who has invented a new evil experiment to capture all of the experiments. Lilo and the team must find a way to defeat him once and for all.—RECB3

Lilo, Stitch, Jumba and Pleakley have finally caught all of Jumba's genetic experiments and found the one true place where each of them belongs. Stitch, Jumba and Pleakley are offered positions in the Galactic Alliance, turning them down so they can stay on Earth with Lilo. But Lilo realizes her alien friends have places where they belong, and it's finally time to say "aloha." Meanwhile, Gantu has left Earth and broken Doctor Jacques Von Hamsterviel out of prison, who's planning to create and clone a new experiment named "Leroy," one that will allow him take over the galaxy.—Anonymous

Jumba, Pleakley, Stitch, and Lilo are hailed as heroes by the Galactic Alliance for having successfully completed their mission to seize and purpose all of the experiments on Earth. Pleakley receives an offer to become chairman of Earth Studies at Galactic Alliance Community College, Stitch is appointed captain of the Galactic Armada and commander of the recently commissioned Big Red Battleship 9000, Lilo is appointed ambassador of the Galactic Federation to Earth and the only defender of the experiments, and Jumba is offered a chance to return to his former laboratory.

At first, Jumba, Pleakley, and Stitch turn down the offers because they do not want to leave Lilo alone and depressed, but Lilo lets them go after realizing how much they miss their latest adventures. Lilo presents Jumba with her favorite Elvis record, Pleakley with a small rock that she can use as a paperweight, and Stitch with a necklace featuring a Ku tick before they depart. Since he was unable to capture all of the experiments-aside from 625-Gantu has determined that he must free Dr. Jacques con Hamsterviel from prison aboard his ship. He departs with a dejected 625 and boards a two-man space shuttle. After learning of Jumba's current situation, Hamsterviel devises a new plan after Gantu successfully frees him.

Although Jumba, Pleakley, Lilo, and Stitch take pleasure in their honors, being cut off from their Hanna causes them to feel depressed and hopeless. Jumba is working on a mold for a new experiment while listening to Lilo's Elvis record. However, Gantu and Hamsterviel storm into his lab and force him to finish with a gun so they can have an experiment as powerful as Stitch. Hämsterviel decides to call the red Stitch impersonator Leroy after Jumba's work.

In the meantime, Stitch, who has been tasked with recapturing Hamsterviel, shows up at Jumba's laboratory and duels with Leroy. Pleakley, however, shows up at the wrong time, diverting Stitch's attention long enough for Leroy to imprison him in a capsule, defeating him. In order to defeat the Galactic Alliance, Hamsterviel then discloses his scheme to clone an army of Leroys. Hämsterviel locks Pleakley, Jumba, and Stitch in Pleakley's G.A.C.C. vehicle and steers it in the direction of a black hole before departing for Turo.

Lilo chooses to get in touch with Stitch on Earth, but she discovers that Gantu's ship has the only intergalactic videophone on the planet. When she gets there, she sees a broken 625 and requests to use the videophone, but it is not working. Lilo comforts him when she sees that he is in pain and gives him the name "Reuben" after one of his favorite sandwiches. The galactic videophone is repaired by him using his newly acquired strength and intelligence. Lilo calls the BRB-9000 to inquire about Stitch's condition. When Lilo discovers that Leroy is not wearing the tick necklace, the ruse fails. Leroy, who has taken over the ship, tries to disguise himself by impersonating Stitch through shape shifting. Upon reminding Hamsterviel of the danger posed by the remaining Experiments, Gantu orders Leroy to go to Earth and seize them all. Lilo asks Reuben for assistance in repairing Gantu's ship after noticing that Stitch is in danger. Initially reluctant, he quickly and effectively fixes Gantu's ship by using his powers, which are comparable to Stitch's.

Stitch breaks out of his capsule and releases the others as the G.A.C.C. vehicle approaches the black hole. The navigational computer is still locked on the black hole course, though. Jumba mentions that they can throw a small object into the hole to break the event horizon, so Stitch takes Pleakley's rock and tosses it just before they are sucked in.

On Earth, Leroy finds and seizes Lilo's scrapbook of the experiments, swiftly apprehending them as well as Lilo's adversary, Mertle Edmonds, who owns Gigi, another experiment. When Lilo and Reuben get to Turo, they discover too late that Hämsterviel has taken over the Galactic Alliance and that the Grand Councilwoman has been demoted to his receptionist after usurping it. He then gives Gantu the order to put the two of them in jail. But now that he knows Leroy completed the capturing task more quickly than Gantu, Hämsterviel dismisses him. A few moments after changing his mind, Gantu helps the two flee. The group is surrounded by Leroy clones when the G.A.C.C. vehicle unexpectedly emerges through a wormhole, saving them and bringing Lilo and Stitch back together. Without any time to explain, Gantu, Reuben, and Lilo all get into the car and leave for Earth.

Leroy has collected all of the experiments at Aloha Stadium on Earth. Hamsterviel announces his plan for all the experiments, and then the BRB-9000 shows up. He gets ready to destroy them until the heroes get there in time to destroy the ship's main cannon. But when Hämsterviel admits that he brought his Leroy army as a backup, an epic conflict breaks out between them and the experiments. The Leroys quickly prevailed because of their superior numbers, even though the experiments had some early successes. After pondering how to put an end to the Leroy army, Jumba recalls that he had given Leroy a covert shutdown command: Aloha 'Oe" by Elvis Presley. When this song is played, Leroy and his clones will deactivate. Having a plan, Stitch breaks up the fight and, dressed as Elvis, sings Aloha Oe with Lilo and Reuben by his side, making the Leroys all stop working and shut down. After his scheme is once more thwarted, Hamsterviel is apprehended and returned to prison.

As the alliance once again recognizes the team for their triumph, Pleakley, Jumba, and Stitch request permission to bring Lilo back to Earth. This is granted by the Councilwoman, who then asks Gantu if he wants to be restored as the Armada's captain. Gantu agrees, but only if Reuben is given the role of galley officer. This ends the experiment. When Mertle and Gigi return to Earth, Lilo prepares for a final Hanna photo. Gigi only agrees after learning that her dog was always an experiment. Lilo's Hanna, which includes all of Stitch's cousins, is the final photo in the album.

Leroy and his clones are positioned in separate cells around Hamsterviel in the film's climactic scene. They have recovered and start dancing to Jailhouse Rock. A comprehensive list of Jumba's experiments, ranging from 001/Shrink to 626/Stitch, is displayed on the left side of the screen as the credits roll. Lilo (and other characters in certain cases during Lilo & Stitch: The Series) provide the names of each experiment.