The responsibility for caring for six-year-old Lilo Pelekai falls on her older sister Nani. Nani has to work and study a lot, so the girl is often left alone. One day, a neighbor suggests that she adopt a dog from a shelter to help the girl cope with her loneliness. However, Lilo brings home a cute alien instead of a dog from the shelter. The girl names her new pet Stitch, but on his home planet he was called Experiment 626. He is a fugitive from the galactic police and a product of genetic experiments, distinguished by his tendency toward destruction, his ability to learn quickly, and his near-invulnerability.