Ash and friends stop at a Pokémon Center, Dawn hears on TV that Kenny and Nando have scored the newest Contest victories. Dawn is eager to train Piloswine for the contest in Chocovine Town. Ash and his Pokémon train to pass the time. Dawn decides to train with them as well, deciding to use Piloswine for the first time.
Ash is training on the battlefield for his sixth badge, but as Dawn calls out Piloswine, it refuses to obey her commands, though she dismisses this in the beginning careless. She commands her Piloswine to use Takedown, though it uses dig to hide underground. Piplup volunteers to retrieve Piloswine, and manages to get it above ground. Brock suggests that it might just be hunger. Therefore Dawn gives it Poffins. But after she stops Piloswine charges at her for more, whilst knocking Piplup out of the way. Dawn and Ash begin running, as Piloswine charges and attacks them. Gliscor volunteers to help but is ignored by Ash as he commands Grotle to help. Grotle stands ground while being half-frozen with Ice Shard. Ash then calls forth Gliscor to use Screech. Gliscor manages to get partially frozen, but the ice melts away as it uses Fire Fang (which is then used to free Grotle). Piplup is again catapulted by the rampaging Piloswine and is saved by Gliscor. Then Brock calls out Happiny to stop Piloswine dead in its tracks with its unusual strength. Ash suggests to have a battle with Piloswine.
As Piloswine and Grotle battle, Piloswine constantly refuses to listen to Dawn's attacks and attacks on its own, revealing that it is able to use Ancient Power. Suddenly an aroma sweeps by Mamoswine, causing it to rampage out of the battle to the scent. It is revealed that the scent is from Team Rocket's spongecake. As they are about to eat, they are hit with Piloswine's Ice shard and blasted away. Ash and co. catches up with it, and calms it down.
Back at the Pokémon Center, Dawn sadly ponders over her problems with Piloswine, wondering how it will be able to compete in the contest. She is comforted by Ash and Brock, reassuring her to be calm and that they would become buddies. Spying behind a window, Team Rocket realize that it was Dawn's Piloswine, and create another scheme to stage. Inside, Jessie and James, dressed as "punks" become excited over a poster for Pokémon Friendship School, making sure to catch the group's attention. Dawn then realizes that the school can help her and Piloswine become closer.
They approach the school, to be confronted by Jessie in disguise. Jessie clamors about the exceptional friendship school. She leads the group into a tent filled with many obstacles. They each are told to choose one Pokémon to befriend. Ash chooses Grotle, Brock chooses Croagunk, and Dawn chooses Piloswine. But as Ash and Brock are properly maneuvering through the obstacle, Dawn's Piloswine simply avoids them, and sometimes will not move unless given a Poffin by Dawn.
After they reach the outside of the tent, they are brought down a cliff to the ground on a lower level to begin their "Friends Forever Course." They are met by James barely in disguise, who tells Ash and co. to release all their Pokémon. James then tells them to do "Comprehensive Calisthenics" to establish Pokémon synchronicity. He then raises flags and maneuvers them into various postures. He then asks the trainers and their Pokémon to move into the two circles, trainers in the white cirle, and Pokémon in the red circle, directly to the right. Piloswine has to be pushed by Piplup as it still refuses to move. James then continues and forms a ball form. As everyone crouches down to do the same, Meowth and Jessie (watching nearby atop the cliff) activates a hole beneath the trainer's circle (but unlike the usual holes, this one was very short and easy to climb out of). Then a part of the cliff opens with a cage appearing and trapping the Pokémon. Team Rocket then recite their usual theme. Their balloon then rises, lifing the cage with the help of twin motors. Ash and co. then command their Pokémon to attach the cage bars, without success. But the electric charge of Pachirisu's Discharge jolts Piloswine, whom begins shaking the cage about, lowering the balloon and eventually crashing it. Jessie and James then call out Yanmega and Carnivine (who again begins chewing on James's head) to attack the Pokémon within the cage. But after a direct hit from Yanmega's Silver Wind, Piloswine begins to evolve (into Mamoswine). The mere size of Mamoswine is enough to break the cage. Jessie and James begin directing their attacks at Mamoswine, who uses Ice Shard to freeze them, and blasts them away again with Take Down. It then begins charging at Ash and co. Piplup then attempts to stop Mamoswine, failing again. But then Dawn is able to have Mamoswine return to its Poké Ball before being hit. She then ponders of whether she will ever be able to control Mamoswine, but is reassured by Ash and Brock.
Back at the Pokémon Center, Nurse Joy then announces to Ash that Byron has returned to his Gym, who was absent when Ash previously came. Ash and his Pokémon excitement increases as they become anxious to get their sixth badge.