Spongebob and Friends meet Lilo & Stitch is a film about a young Hawaiian girl who befriends Stitch, a mischievous blue alien that crash-landed on Earth. Stitch, as well as the Shell Louge Squad, comes to understand the concept of 'ohana (family) and has great adventures with Lilo, but they must be vigelent, as the Villain leage seeks to contain Stitch to turn him into an ultamate guard dog for the leage.
Dr. Jumba Jookiba is put on trial by the galactic governing body for illegal genetic experiments, including his latest creation, Experiment 626: an aggressive and cunning creature that is nearly indestructible. Jumba is imprisoned while Experiment 626 is set to be exiled on a desert asteroid. However, during transport on Captain Gantu's ship, 626 manages to escape to the Planet Earth (despite having guns that are encoded with his DNA and designed to only shoot him pointed on him). when Stitch excaped, Galaxhar's advanced Teclogigly quickly picked it up, allowing him to capture the latest in the villain leage's long line of monsters. The Grand Councilwoman orders Jumba to work with Agent Pleakley to recover 626 discreetly, with Cella secretly went along against the Grand Councel Woman's wishes. 626 survives his escape attempt to Earth, landing on the Hawaiian island of Kauai, but is knocked unconscious by a passing truck, and is taken to an animal shelter because he is believed by the truck drivers to be a breed of dog. After the recent death of their parents in a car accident, 19-year-old Nani Pelekai is looking after her younger, more rambunctious sister, Lilo, and the shell louge squad, who sent to vacation their after the dinosaur mission. They are visited by Cobra Bubbles, a social worker, who is concerned that Nani cannot take adequate care of Lilo. He considers putting Lilo into foster care, but Nani is very much against this idea, as Lilo and she are the only remaining members of her family; Lilo does not help as she does not understand what may happen. After hearing Lilo in her room pray to be given a friend (Lilo has no "real" friends because every girl in her class bullies her), Nani agrees to allow Lilo to adopt a dog. At the shelter, Lilo immediately takes a keen interest in Experiment 626, despite serious misgivings that Nani and the shelter worker have about him being a dog. Lilo names 626 "Stitch," and shows him around Hawaii; Stitch quickly discovers escape is impossible as he would sink and drown past the island to the sea. As Nani attempts to find a good job, she is forced to bring Lilo and Stitch with her. Lilo uses the time to try to curb Stitch's aggressiveness by encouraging him to behave like Elvis Presley, whom she calls a "model citizen." Stitch's antics ruin Nani's chances of getting a job. David, a friend of Nani's, sees her at the beach, where she was trying to get a job as a lifeguard, but failed, this time, by a Kuwahgamon attack. Cobra saw the whole thing and tells Nani he will come by in the morning to take Lilo away from her. After Stitch sees of the villain leage's impending attack, he leaves, with Lilo saying "I'll remember you though. I remember everyone who leaves." The next morning, as Nani waits for Cobra to arrive, David tells Nani of a job offer that she must respond to. Nani tells Lilo to stay at home while she goes to secure the job. Stitch, hiding in the nearby woods, encounters Audrey 2, one of Galaxhar's required Allies, who tried to captured Kairi before stitch, but foiled by the efferts of Sandy (and in a lesser exsent, Spongebob) Stitch and the gang races to Lilo's house, followed by the Space Pirates firing at them with guns. the Louge and the leage fight, while the Space Pirates and Clones were quickly defeated, Audrey 2 was a real challnged till Izzy found his weak point, the prime vine, which Thundera ang Kabutarymon attacked. The house is ultimately destroyed by the end of the fight, with Nani and Cobra returning shortly after. As Nani and Cobra argue over Lilo's well-being, Lilo slips away with Kairi in persuit, to hide in the forest and finds Stitch, who reveals his true alien form to her. Whilethe louge discus how to prepare for the next villain leage attack, Lilo, Stitch, and Kairi are captured by Captain Gantu, who Galaxhar and Scroop corrupted and they intend on to leave Hawaii to return to the leage base. Nani is shocked to see Gantu putting Lilo, Kairi, and Stitch in a container pod and taking off in the ship. Stitch, however, escapes from the container before the ship takes off. Nani then realizes that Stitch isn't what she thought he was, and demands he speak, just as Lilo always said he did. While once again trying to capture Stitch, both Jumba, Cella, and Pleakley are revealed to Nani, and tell her that they do know Lilo, and they can both get her back. Stitch, with help from Jumba's ship and by launching a gas tanker truck out of a volcano, is able to free Lilo and stop Gantu, Galaxhar, and Scroop, with Spongebob's help. After they land, they find that the Grand Councilwoman has arrived nearby, in order to capture Stitch personally. However, when she sees Stitch has learned to talk and bonded with Nani and Lilo, she realizes he has become a civilized creature. Using Lilo's certificate of Stitch's ownership as proof, the Councilwoman asserts that Stitch is now a part of Nani and Lilo's family, and lets him live his exile on Earth with the humans as his warders. As her guards take Gantu, Galaxhar, and Scroop away, she doesn't let Pleakley or Jumba return on her ship, and lets Cella become the family guardian, and orders Cobra, a former CIA agent who previously met the Councilwoman at Roswell, to keep an eye on the new family. Stitch, Jumba, Pleakley, and Cella become integrated into Lilo's family, and the Shell Louge Squad began to bond with one another more then just a group of misfits, but a family in a metiforitcal and team sense, and the house is rebuilt with the help of the bunch.
There is also a side story, but the main story's the main focus.