Ash and Goh have come to Castelia City to indulge in an all-you-can-eat tour as a part of Goh's prize for winning the Pokémon Grand Eating Contest. Lying in wait, a disguised Team Rocket has set up a fake Casteliacone van in a bid to steal Pikachu. Meowth reveals his latest scheme to his teammates, they plan to switch the real Pikachu for a life-like mecha called "Practically Pikachu". Jessie and James are impressed by Practically Pikachu's likeness, but quickly spot one flaw: it keeps saying "Hika" instead of "Pika". Meowth admits the cry was the only thing he couldn't replicate perfectly, hence the robot's name. Jessie sneers as she admits that Ash will be too dumb to notice the difference.
Ash and Goh finally arrive at the van window, so Team Rocket gets into their positions. Jessie takes the orders, giving the boys a vanilla-flavored ice cream each. She announces that it is Casteliacone's anniversary today and offers them a special bonus to celebrate. Goh says that he prefers plain vanilla. Ash falls for the trap, and gladly accepts the bonus offer, so several more scoops of pink ice cream and fruit are added to his cone. Sitting down on a park bench to enjoy their desserts, Ash decides to leave to wash his hand clean, leaving Pikachu in Goh's care. Team Rocket quickly enact their plan, placing Practically Pikachu beside Pikachu before making the swap. Unexpectedly, the two Pikachu run off and start playing together, making the situation confusing. Goh is distracted, meanwhile, by the fast-melting ice cream. Meowth and his teammates try listening out for the difference in cries before one of the Pikachu coughs on its food and says "Hika". They snatch the other Pikachu and ride off on a bicycle. While Ash returns, unsuspecting of anything amiss, Cinderace and Lucario chase after Team Rocket after spotting Pikachu has been kidnapped. Meowth launches some sticky goop to slow them down, however, Lucario and Cinderace, who have been struggling to get along, find themselves stuck together by their wrists. The rubber-like goop helps the pair ricochet off several light poles, before managing to rebound and rescue Pikachu.
Ash and Goh move on to their next Unova delicacy, Watchog buns; crunchy fried batter with mustard stripes on a stick. Lucario and Cinderace, meanwhile, find themselves at a dead-end with Team Rocket approaching in their Meowth balloon. Cinderace and Lucario try to go in opposite directions, which sparks an intense argument between the two. Meowth fires another goop bomb at them, though this only enables the pair to escape the alleyway, still with Pikachu in hand. The now-extended goop leads Lucario and Cinderace to bounce off several more poles across Castelia City. As Team Rocket tries to survey the area from the skies, Lucario and Cinderace eventually crash straight into them, sending them all blasting off into the distance.
Ash and Goh continue to indulge in more food, this time enjoying some Crustle cakes; alternating layers of chocolate sponge and cheesecake with sweet icing that resembles a Crustle's shell. Goh adds that there are also bite-sized Dwebble cakes. While the boys and Pikachu enjoy the cakes, they remain unaware that Lucario and Cinderace are in danger. Ash jokes that the two have probably stuffed themselves full and cannot move.
Eventually crash-landing in another part of the city, Team Rocket summon the Rocket Prize Master, receiving a Sawk and Throh to take on Lucario and Cinderace. Sawk makes the first move, attacking with a Low Sweep. Cinderace leaps up to avoid the blow, but Lucario instead takes the hit to the ankles. The pair, still attached at the wrists by the goop, is consequently battered away. James orders Throh to use Circle Throw, tossing the pair. Lucario manages to get to its feet, but Cinderace cannot stop its momentum and crashes into its partner. The goop continues to cause havoc for Cinderace and Lucario, as neither can agree on a counter-tactic. Sawk and Throh deal more damage with Brick Break and Vital Throw attacks, respectively. As Jessie remarks that the two look pathetic while stuck together, Cinderace becomes inspired to collaborate with Lucario. Without much warning, it twirls Lucario around before throwing it towards Team Rocket. Lucario recovers from its dizziness and lands Reversal to knock Sawk out. Lucario follows suit, swinging Cinderace to build momentum before Cinderace defeats Throh with a Blaze Kick. The goop has finally reached its optimum stretch and breaks away, leaving Cinderace and Lucario free of any restraint. Together, they launch a Pyro Ball and Aura Sphere combo to send Team Rocket blasting off. Lucario and Cinderace then turn to check on Pikachu, only to see that he is now missing. While blasting off, the Rocket trio notices that Wobbuffet nabbed Pikachu during the confrontation. Jessie is initially thrilled, until Pikachu calls out "Hikachu", revealing that it's actually the Practically Pikachu robot. Meowth remarks that the robot proved to be a great replica after all, much to the infuriation of his teammates as they blast off together.
Cinderace and Lucario rush back to the park in a panicked state. However, they are stunned to see Pikachu happily snacking beside Ash and Goh. As the pair collapse from shock, Ash believes they must be hungry, so Goh gives Cinderace a bag of snacks to enjoy. As Cinderace enjoys the food, it tries to get Lucario to try one for itself. Lucario is unimpressed when Cinderace pushes the snack into its face. It reacts in a rage and chases Cinderace down in retaliation. Ash and Goh remain unaware of Lucario and Cinderace's fiery rivalry, even remarking that the pair appear to get on well.