As our heroes head towards Veilstone City, Ash's new Chimchar struggles to adapt to its new surroundings. Everything is the complete opposite of life with Paul: mealtimes are fun and everyone treats each other with friendship and kindness! Chimchar still has vivid memories of the lonely and harsh treatment it received from Paul, so this sudden reversal of fortune is nearly too much to take. When Ash even praises Chimchar after it loses a practice battle with Dawn's Piplup, Chimchar breaks down in emotion.
Meowth, who's searching for Team Rocket after their group was split up by some rampaging Zangoose, sees this scene and has a pang of sympathy for Chimchar. That night, Chimchar can't sleep and it finds Meowth sitting in the moonlight. Meowth isn't in the mood for a fight; instead, it gently tells Chimchar to make the best of its new life. Of course, all bets are off the next morning once Meowth rejoins Jessie and James: they catch Dawn and Brock by surprise, then try to steal all of their Pokémon by trapping them in giant canisters!
But when the Zangoose show up, Team Rocket has to hide in the canisters for their own protection. Ash and Chimchar reach the scene and realize the Zangoose are about to knock the canisters off a cliff! Chimchar has encountered Zangoose before and it's still afraid of them. Ash knows this, so he encourages Chimchar and gives it the confidence it needs to take on and defeat the Zangoose. With everyone safe and sound, it's three cheers for Chimchar, who finally feels like a part of its new family!
Ash, Dawn and Brock settle down for lunch while still on the road to Veilstone City. The gang decides to let their Pokémon out for the day, and soon, everyone is starting to set up for lunch. However, Chimchar is confused on what to do since everyone is in a happy mood. It remembers mealtimes with Paul, which involved Paul feeding Chimchar directly from a tin while angrily telling it to hurry up. As everyone else begins eating, Chimchar has to be prompted by Ash, making it clear the Pokémon is having trouble adjusting to its new circumstances.
Team Rocket also have their respective Pokémon out of their Poké Balls, eating with them. However, meal time is interrupted when Seviper notices that three Zangoose are heading their way. They begin fighting furiously and Seviper, despite attacking its mortal enemies, finds itself outnumbered and outmatched. Jessie returns Seviper to its Poké Ball, but it refuses to give up and comes straight back out. Jessie continually tries to get Seviper to return, but to no avail. Then, the wild Zangoose send Team Rocket blasting off again, with Meowth landing in a different area from Jessie and James.
With most of their Pokémon lounging about, Ash and Dawn go for a sparring match - all watched by Meowth as he looks for his teammates. Ash uses his Pikachu and Dawn uses her Buizel. After a tough match, the two compliment their Pokémon and Chimchar is reminded again of how it once managed to defeat Elekid during training, but still got scolded by Paul since it did not access Blaze to do it. Ash and Dawn decide to have another battle using different Pokémon, as Ash selects Chimchar to battle against Dawn's Piplup. Despite putting up a tough fight against Piplup, Chimchar loses the battle, causing it to be reminded of losing in the Tag Battle Tournament and being cruelly released by Paul. Ash picks up Chimchar, who expects to be criticized, but Ash instead congratulates it on a good battle. This is followed up by compliments from Dawn and Brock, as well as cheering from all the other Pokémon. Chimchar is left very nervous and confused, and starts crying since it cannot handle its drastic change in environment. Ash is confused as to why Chimchar would cry when it is getting complimented, and Brock muses that Chimchar must not have got many chances to show any emotion while under Paul's ownership. Ash understands, and holds Chimchar while it sobs its heart out. Meowth is also moved by this emotional display and, with tears in his eyes, leaves without incident to continue looking for Jessie and James.
That night, Chimchar has a nightmare about having to fight under Paul's command battling a Graveler. Graveler jumps out against Chimchar and uses Rock Throw, sending boulders flying. Paul orders Chimchar not to move, as his way of trying to force Chimchar to access Blaze. Chimchar's nightmare then switches to the Zangoose fight before it was caught, still with Paul's voice in its head. Chimchar jolts awake and, unable to get back to sleep, goes for a walk.
Meowth is still looking for the rest of Team Rocket when he crosses paths with Chimchar. After convincing it he does not want to fight, Meowth tells Chimchar that he knows what it is like to worry, and he dreams of the time when he and the others are finally able to capture Pikachu, as then he would not have anything to worry about. Meowth then tells Chimchar it should stop worrying about the past, and instead look to the new, brighter future, because it is a very lucky Pokémon. Meowth states to Chimchar that its new friends would do anything, even "give you the shirts off their backs if they had to", before he leaves. Chimchar is left thoughtful at this new outlook. The next morning, all of the Pokémon start helping out preparing for a meal, and Chimchar is once again left unsure of what to do. Ash calls over to it, asking for help carrying some water, to which Chimchar happily agrees to.
Later, Team Rocket is shown in their balloon, retrieving Meowth by his rear end with a "plunger". They state that were going to steal Ash's Pokémon and that meeting Meowth was just a coincidence, then go through with their plan to capture the gang’s Pokémon while are out of their Poké Balls. As they begin to fly off with the Pokémon in canisters, Dawn tries to make her Pokémon return into their Poké Balls, but fails. Meowth says the containers are protected from that, so Dawn commands Piplup it to use Bubble Beam while Brock orders Croagunk to use Poison Sting. This also fails.
Seviper, however, gets out of its Poké Ball because it senses the three Zangoose once again. The gang of Zangoose climb up a tree to reach Seviper, and rip the balloon apart, sending them crashing to the ground. Team Rocket decide to hide themselves within one of the containers, but this backfires, as the wild Zangoose attack the container, attempting to get to Seviper, and push it close to the edge of a nearby cliff. Ash and Chimchar arrive back and see what is happening, and Ash tells Chimchar to help. However, Chimchar is too frightened to fight the wild Zangoose. Ash gives a little pep talk to Chimchar, telling it that while he understands Chimchar is scared, the other Pokémon really need help. Chimchar is reminded of the kindness shown by Ash and the others, and Meowth telling it that the group would do anything to help it if they needed to. Ash tells Chimchar not to worry about the power of Blaze, as it just has to believe it can win. As a result, Chimchar becomes motivated to battle against his fear, the Zangoose. Chimchar uses Dig a few times to confuse the Zangoose and then uses Flamethrower to finish them off.
With the Zangoose defeated, Team Rocket open the container from the inside and try to escape, but Ash and Dawn command Pikachu to use Thunderbolt, Chimchar to use Flamethrower, Turtwig to use Razor Leaf, Piplup to use Bubble Beam, and Buneary to use Ice Beam to attack Team Rocket, sending them blasting off for the second and final time. Chimchar joins the other Pokémon in their cheering, and with its past completely fading away, the heroes' journey continues.