Stitchman Meets Bonnie and Clyde is the twenty-fourth episode of Stitch!-The Mischievous Alien's Great Adventure.
Yuna, Stitch, Pleakley and BooGoo, as well as Kenny, Ted and Marvin, are at a live performance of a television hero named Goodman. He rescues a damsel in distress by stopping four villains trying to hurt her. After the show's over, a truck full of possessions is stolen. Stitch and Pleakley try to convince Goodman to stop the thieves and, thinking it to be good publicity, he tries, only to pull a hamstring.
Tigerlily then arrives and brings Yuna and Stitch home to do chores. Stitch and Yuna protest, only for Tigerlily to pull out a failed fraction quiz Yuna took in school. Tigerlily threatens to show it to Grandma unless Yuna and Stitch clean the house. Stitch comes up with a plan to "accidentally" splash a bucket of water onTigerlily and get the quiz out of her jacket pocket when she takes it off, but she knows what they're planning. Suddenly, steam fills the room as the two crooks from before steal Yuna's quiz and a special possession of Tigerlily's in a purple case. Stitch recognizes them as two of his cousins: Experiment 349 AKA Bonnie and Experiment 350 AKA Clyde. He puts on a superhero costume and calls himself "Stitchman" (inspired by Goodman) and pursues them.
Bonnie and Clyde sneak into Penny's house and take a scrapbook she was looking through, as well as Kenny's diary. The two theiving experiments congratulate themselves, and even though Clyde points out that there's too much stuff on their truck and the stolen things are starting to fall out, Bonnie assures him that they can just steal it again. Stitch runs alongside their truck and tells them to stop, but they don't listen and speed ahead. Penny and Kenny catch up and the former throws Stitch up to them, but he gets stuck on the windshield and is merely wiped off. When he tries again, Bonnie throws him off their trail by feeding him a pork sausage link until it runs out.
Later, a crowd of townsfolk surrounds Officer Suzuki as they complain to him about their possessions being stolen, Tigerlily and Penny especially. Even Sasha was robbed of her homework pencil. Pleakley expresses his concern and Jumba gets a news update on a handheld device. Yuna, Pleakley, Sasha and Stitch watch as the reporter announces Bonnie and Clyde's escape from space jail. Suzuki suggests that the people of the island work together to catch the thieves. As an incentive, he offers a plastic badge to whoever brings Bonnie and Clyde to justice. Stitch, Pleakley, Ted, and Marvin want it, but Penny and Kenny just want their respective possessions back. They then see Bonnie and Clyde driving away and everyone starts running after them. Gantu and Reuben also see them, and despite miraculously having the day off, Gantu tries to capture Bonnie and Clyde for Hamsterviel, but they just steal his uniform instead.
Stitch, Yuna, Sasha, and BooGoo are in a group trying to find Bonnie and Clyde, whose trail they eventually pick up due to the stolen property falling out of the truck. The two thieves decide to go back to their secret layer. The bridge over a chasm they need to cross is closed, but they just go another way. Yuna's group sees them and follows them. Bonnie and Clyde arrive at their hideout, which is one of the Twin Caverns. To their surprise, it's filled with jewels that neither of them stole. Kijimunaa arrives and explains to them that he's gathering jewels for a yokai festival. Bonnie and Clyde play along and say that they're tourists who had come to see the festival. Bonnie then claims that Clyde's been having intestinal attacks. Kijimunaa then leaves to go collect some healing herbs. He comes across Stitch and the others, but when he tries to explain the situation to them, they point out that Bonnie and Clyde are theives, and they see the two drive away again with the jewels for the festival. Yuna and Stitch find new resolve to catch them.
Bonnie and Clyde decide to leave the island, but they see a giant pineapple on the side of the rode and decide to steal it. When they get out though, the pinepple turns out to be Penny in disguise, who had set up a trap. Her entourage are about to capture Bonnie and Clyde in a net, but Gantu grabs them instead. He puts the two in a container, but Stitch faces him. After a short battle, a tree falls on Gantu's head, driving him into the ground. Stitch releases his cousins and Pleakley begins to call the galactic police to report their capture. Bonnie suddenly doubles over, saying that she doesn't feel well. Everyone, even Clyde, thinks that she's faking at first, but Stitch feels her forehead and claims that she really does have a fever.
Yuna and Stitch take Bonnie and Clyde back to their house, where they let Bonnie rest and give her some canned soup with Kijimunaa's healing herbs added. Bonnie and Clyde explain that they were able to escape from jail when the guard sneezed (likely giving Bonnie her cold) and dropped his keys near their cell. The two say that they've tried to be good, but it's hard for them. Stitch encourages them by saying that doing good deeds can be fun. The two promise to change their ways. The others leave Bonnie and Clyde alone. They suddenly notice alien police cruisers hovering outside the house looking for them. They resolve not to be caught again.
Stitch and the others find Penny and Kenny looking through Bonnie and Clyde's truck for their scrapbook and diary respectively. The two siblings badmouth Stitch's cousins, but Yuna, Stitch, and Pleakley assure them that they've reformed. Unfortunately, unbeknownst to anyone, Bonnie and Clyde sneak back into the truck, having decided not to go good yet. They drive off again, leaving Stitch very frustrated. Jumba then arrives in a car with a robotic crane attatched. Stitch, Yuna, and Pleakley climb in and give chase. Penny in a helicopter from her father's factory and the alien police join the chase as well. Jumba tries to grab their truck with the crane on his car, but has no luck. The closed bridge soon comes up again, but Bonnie and Clyde decide to go for it anyway. They drive through while Jumba stops and Stitch jumps out. Despite Stitch's warnings, Bonnie and Clyde keep driving across the bridge, but it breaks, sending them down into the abyss below. Fortunately, Stitch grabs their truck and saves them. When they ask why, he reminds thiem of what he said before: that doing good is fun. Bonnie and Clyde both smile as the alien police cruisers surround them.
Back in jail, Bonnie gets a gift from Pleakley: it's more of the herbal soup. Bonnie and Clyde decide to go straight after all, but then the guard drops his keys again. Clyde asks if they should give them back, but the two just chuckle.
Down on the island, Stitch wins the badge for bringing the theives in; he gains a good deed as well. He then tries to give Yuna, Penny, Kenny, Tigerlily, and Sasha, their possessions back, but he mixes them all up. He gives Yuna Penny's album, which shows that when she was a baby, she was fat and odd-looking. Penny retorts by mocking Yuna's failed quiz, which Stitch had given her. Tigerlily gets Kenny's diary and she reads a part that describes how he's attracted to her; Kenny nervously tells her that he "knows whose it is". Finally, Sasha gets Tigerlily's possession, which turns out to be a facelifter. Tigerlily, Penny and Kenny get furious at Stitch for embarrassing them, and the episode ends with the three chasing him.