As Ash and his friends continue towards Olivine City, they notice someone hidden in the grass, looking for something while holding a net. They approach the young boy and learn that he is trying to catch a wild Dunsparce. Brock asks if he has any other Pokemon to assist, and the boy calls out his Caterpie. However the Bug Pokémon immediately frightens Misty, who cowers behind a rock. The boy introduces himself as Bucky, and the others introduce themselves to him. Misty asks Bucky why he's looking for a wild Dunsparce, but before he can answer, a group of kids Bucky's age walk by, each with a Dunsparce of their own. The boy leading the group, Timothy, invites Bucky to go to the park so that they can all play with their Pokémon, and Bucky replies that he'll join them soon. Ash’s group and Bucky venture over to the park where the children brag and compare each other’s Dunsparce. Brock mentions that every kid in town seems to have a Dunsparce, and Bucky despondently acknowledges this. He explains that a swarm of Dunsparce appeared in the area while he was away from town to visit his ill grandfather. Bucky adds that he has searched for one ever since, but he hasn't found a Dunsparce yet.
Timothy and the other kids challenge Bucky to a Dunsparce obstacle race. Aware that Bucky doesn’t have a Dusparce, they allow him to use his Caterpie. The Pokémon are all standing at the starting line, though Caterpie is shown to be noticeably smaller than its competition. The race starts, and all of the kids cheer on their own Pokémon. Caterpie lags significantly behind all the Dunsparce, despite putting in its best efforts. Team Rocket watches the Dunsparce race from behind the bushes. Meowth and James note that there are so many Dunsparce, but Jessie reminds them not to get distracted, since they have to focus on getting Pikachu. Her teammates agree and they duck back into the bushes to complete the finishing touches for their latest plot. Meanwhile, Caterpie struggles to climb up a bunch of steps, while Bucky motivates it to keep going. Caterpie sees a Dunsparce right behind it, and Dunsparce's owner tells it to fly right over Caterpie. It does so, easily getting to the top of the steps and sliding down the slide. The boy cheers and turns to Bucky, telling him that Caterpie is already one lap behind. Bucky keeps telling Caterpie to not give up. However, Caterpie loses its balance and falls down the steps, knocking itself out. Bucky decides that Caterpie needs to rest and leaves the race, saying farewell to his friends.
While walking away, with Ash and his friends following closely behind, Bucky tells Caterpie not to worry and to have a good rest. He returns Caterpie to its Poké Ball. Ash, Misty, and Brock all volunteer to help Bucky find a Dunsparce so that he can play with the other kids. Ash sends out his Chikorita, Totodile, and Noctowl, Misty calls out her Poliwhirl, and Brock orders his Golbat to assist in the search for a wild Dunsparce. Togepi walks happily before it sees some soil popping out of the ground. Suddenly, the soil moves in a different direction, and Togepi happily follows it until it reaches Pikachu. Pikachu pats the soil, curious, when a Dunsparce pops out of it. Bucky happens to pass by and is surprised that he finally found a Dunsparce. Ash tells him not to let it get away, but the momentary distraction allows Dunsparce to dive back into the ground. Everyone gathers around the spot where Dunsparce hid, and they decide that they'll just have to dig it back out.
While Totodile, Chikorita, Togepi, and Pikachu are staring at the spot, a net from Team Rocket's Meowth balloon drops down and captures them. When Ash and Bucky wonder what's going on, Team Rocket recite their motto while dressed in pirate costumes, which Meowth reveals is because of a mix-up at the dry cleaners. James pulls up the net, satisfied with the selection of Pokémon they captured. Ash has Chikorita use Razor Leaf, but it doesn't cut through the net because it is coated in steel. At that, Ash decides to send out Cyndaquil and has it use Flamethrower. It successfully breaks off the net, freeing the Pokémon. Misty has Poliwhirl use Water Gun, which hits the balloon and sends Team Rocket crashing onto the ground. Meowth lands next to a lump of soil that Dunsparce then pops out of. Ash has Cyndaquil use Flamethrower, which causes an explosion and blasts Team Rocket off, with Meowth holding Dunsparce. As Team Rocket is flying through the air, Meowth notices that they got a Dunsparce, and they all scream that it's better than nothing. Bucky on the other hand is disappointed, though Misty and her friends agree to keep on searching for a Dunsparce, which cheers Bucky up.
Meowth is pleased with his caught Dunsparce. Though Jessie is not amused, since she believes that Dunsparce is a boring Pokémon, but Meowth argues that it's better than no Pokémon at all. James says that the Boss would hardly notice one Dunsparce, but then Jessie figures that the Boss would notice dozens of Dunsparce. With that, Team Rocket puts a new plan into action, a "3-D Virtual Pokémon Show" to capture the other childrens’ Dunsparce. The kids, who are playing with their Dunsparce, decide to check it out, hoping to see things like moving holograms or computer-controlled puppets. However, when the curtains open the story of Dunsparce versus Moltres proves to be underwhelming. James and Meowth’s Moltres and Dunsparce costumes are obvious, and their staged battle proves to be cringe worthy at best. Following the performance, Jessie and James roll their trade machine onto stage and offer to trade everyone a Moltres each in exchange for their Dunsparce. The kids are all a gasp at the idea, but Timothy prompts all the other children, with exception of one girl, to follow his lead and trade away their Dunsparce.
Meanwhile, Ash and his friends have been looking for a Dunsparce for hours, but have been unable to find a single one. They walk along the forest when they come across Bucky's friends crying. Bucky asks his friend Timothy why everyone is crying, and Timothy explains the situation. The Poké Balls that were traded to them were all fakes, so Team Rocket took all of the Dunsparce while the kids got nothing. Misty asks the kids to describe the two people that tricked them, and the group realize that Team Rocket are behind the dastardly scheme. Bucky is concerned for his friends’ sake, and Ash reassures him that he and his friends will deal with the culprits.
Team Rocket are having their own troubles with the Dunsparce. James admits that he was only following instructions, but Jessie clarifies that she only wanted him to check on them. Ash, Brock and Misty catch up with Team Rocket and confront them head on. Ash sends out Totodile and has it use Water Gun, but Wobbuffet sends the attack right back. Misty calls on her Poliwhirl and has it use Water Gun, but Wobbuffet uses Mirror Coat again, sending it right back. Then, Totodile uses Water Gun again while Wobbuffet is unprepared, and successfully hits it. James then sends out Victreebel to have it help out, but it latches onto him instead. Just then, all of the children arrive at the scene, and the Dunsparce move to return to their Trainers. Jessie sends out her Arbok, who stands in front of the Dunsparce's way. The children decide to use their Dunsparce to battle Arbok, and call for them to use Screech. Arbok freezes up at the sheer noize, and the Dunsparce make their way to their owners. Jessie tells Arbok to stop them from getting away, but the children have their Dunsparce use Glare, completely stopping Arbok from moving. The Dunsparce then use a combined Take Down on Team Rocket, blasting them off.
All of the children rejoice now that they finally got their Dunsparce back. The wild Dunsparce from before suddenly pops out of the ground, and Bucky sends out Caterpie to battle it. Caterpie hits Dunsparce, but Dunsparce knocks it right back. Bucky has Caterpie use String Shot followed by Tackle, and then he throws a Poké Ball at Dunsparce. Everyone watches with anticipation until the Poké Ball stops rocking and finally catches Dunsparce. Bucky cheers, now that he finally has his own Dunsparce. Back at the park, all of the Dunsparce race through the obstacle course again, now with Bucky's new Dunsparce included. Bucky cheers on his Dunsparce, while Caterpie supports Dunsparce from up on Bucky's shoulder. Watching from the entrance of the park, Ash, Misty, and Brock are glad to see Bucky is happy now. Bucky turns around and bids farewell to the group, thanking them for their assistance.