Stitch & Ai follows the events of
Lilo & Stitch and its subsequent film and television sequels up to and including
Leroy & Stitch, set around 2016. The series opens with Stitch being kidnapped by a faction of alien criminals known as the Jaboodies, who want to use him as a weapon to win a space war. The Jaboodies started pursuing Stitch after hacking into the Galactic Federation's database and discovering a previously-unrevealed "
metamorphosis program" that was secretly coded into him. This function causes the experiment to grow into a giant beast with four laser-firing tentacles when his destructive programming is triggered in a large city. However, another warring faction called the Woolagongs manage to steal the data from the Jaboodies, board the rivaling battle cruiser, and attempt to kidnap Stitch for themselves. Stitch is accidentally freed in the fighting, allowing him to escape back to Earth, where he ends up in
China's
Huangshan mountains. In Huangshan, Stitch meets Wang Ai Ling, a spirited local girl who is soon to be separated from her older sister Jiejie by their aunt Daiyu after the sisters lost their parents in the past year. Daiyu desires to move Ai out of the mountains and into the city with her, believing that it would help Ai would become a "proper lady", but Ai loves her home and is resistant to the idea. Stitch quickly befriends Ai, becomes her new "dog", and the two help one another solve their problems; Ai helps Stitch fight off the Jaboodies and Woolagongs, as well as help him look for a shrine that he has been seeing in a mysterious vision. In return, Stitch helps Ai stay in the mountains with Jiejie and ward off Daiyu's attempts to take her away.
Jumba and
Pleakley later arrive in Huangshan, as they are ordered to bring Stitch to the Galactic Federation for security purposes, but Ai and Jiejie convince the two aliens to let Stitch stay with them. Jumba and Pleakley are then given permission to stay on Earth to keep watch over Stitch as they help out his newfound family. The series also features various flashbacks to key scenes in the franchise that appear in "Hello – Goodbye", "Teacher's Pet", and "Monstrosity". The flashbacks consist of closely re-animated sequences, copying the originals to the best of their ability. The flashback scenes are based on scenes from the original
Lilo & Stitch,
Lilo & Stitch 2: Stitch Has a Glitch, and
The Origin of Stitch. In co-ordinance with this, there are occasional appearances from previous characters of the
Lilo & Stitch franchise, including
Captain Gantu, the
Grand Councilwoman,
Cobra Bubbles, the Ice Cream Man, and (in a brief cameo)
Dr. Hämsterviel. ==Characters==