Maylene finally accepts Ash's challenge. Ash uses Staravia, Chimchar, and Buizel against Machoke, Meditite, and Lucario. The battle between Buizel and Lucario ends up in a tie but Maylene still gives Ash the Cobble Badge.

Dawn beats Kyle and May beats Zoey in the semi finals and both have to battle in the finals. In the finals, Dawn faces-off against May in the Wallace Cup. Dawn uses Piplup and May uses her Glaceon. Dawn manages to narrowly defeat May's Glaceon by a fraction. After the contest ends, Dawn earns her second Ribbon! Now that the contest is over, May departs from Ash, Dawn, and Brock once again and goes back to Johto.

Ash and co. are running after Gligar who has been blown away by a gust, and promptly run into Paul. After a huge argument about their different ways of treating Pokémon, Ash challenges Paul to a battle. But when Chimchar is battling Paul's Ursaring, it activates an overpowering blaze. Chimchar also gets confused and starts randomly attacking anyone in its path.

Ash and Co. arrive at a lakeside Pokémon Center. Jessie's Dustox sees a shiny Dustox, and follows it to the lake. Jessie releases her Dustox, allowing it to mate. This is related to the Season 1 episode 21, "Bye Bye Butterfree" where Ash releases his Butterfree so it can mate with a pink Butterfree.

Dawn challenges the gym leader of Veilstone City, Maylene, in hopes of helping Maylene get over her defeat. Maylene defeats Dawn and she and her Lucario regain their confidence.

After a practice battle between Ash's Chimchar and Dawn's Piplup, Chimchar begins to cry because Ash was nice to it even though it lost, and Paul wasn't. Things get worse when a trio of Zangoose attack and Chimchar has to face its fear and eventually defeats them and overcomes its fear of Zangoose. Chimchar also receives some unexpected advice from Meowth about the future.

In the forest just outside Veilstone City, the group witness a young female martial-artist and a Lucario in a fierce battle. The girl is revealed to be Maylene, the city's Gym Leader, at which point Ash immediately asks for a Gym Battle. However, she recently lost to Ash's rival Paul, and is depressed over her defeat. Further insight into the matter is revealed by Reggie, Paul's older brother. Reggie also helps Ash's Staravia learn Brave Bird.

Hunter J has managed to kidnap Riolu. But despite that, Riolu, reveals his whereabouts to Ash, using its Aura. With Rangers Kellyn and Solana joining them, Ash and his friends go to hunt down Hunter J and get Riolu back. However, J is far more formidable than anyone could have anticipated. Will Ash and friends be able to return Riolu back to its kingdom?

Ash and his friends have arrived at the Lake Resort where the Wallace Cup will take place. Zoey also arrives, and competes, too. Right when the contest began, Dawn becomes nervous and has trouble keeping her composure. Meanwhile, May decides to enter with Wartortle, and Ash enters with Buizel. There are cameos of Drew, Harley, Max, Norman, Caroline, and Solidad.

At night, Ash takes a walk near the Lake Valor with Pikachu when suddenly, something in the center of the lake begins to glow, and it turns out that Azelf appears. When Ash tries to approach it, the shadow disappears again. The next day, the second round of the Wallace Cup begins. May's Venusaur is then revealed, and there is a cameo appearance of May's Skitty battling in the second round. Dawn, May and Zoey make it to the semi finals but Ash loses to a tough coordinator called Kyle. After it is Dawn's turn to battle Kyle in the semi-final, she uses Piplup against his Crawdaunt. There are cameos of Norman, Caroline, Max, Kenny and Paul.

With Ash acquiring the Cobble Badge, our heroes decide to spend the night in Veilstone City before heading out. Reggie takes the group to a park with several meteoric stones lie. However, Team Galactic appears and try to steal them for their world domination plans.

Ash and Brock's old friend May, still training to become a Top Coordinator, visits Sinnoh for the Wallace Cup. Upon arrival at the Seven Stars Restaurant, they find out that only those who win a tag-battle against the restaurant's owners can eat there. Ash partners with Brock and win the double combat with a single move. Before Dawn and May's combat, Team Rockets steals all food from the restaurant. May and Dawn partner up and defeat both the Team Rocket and the restaurant's owners, the later by using Blaziken and Piplup together to create a fantastic fire/water combination. There is a cameo from Drew, Harley, and Max.

At the Pastoria Gym Ash challenges Crasher Wake to a 3-on-3 Gym Battle using Pikachu, Turtwig and Buizel, while Wake uses Gyarados, Quagsire, and Floatzel. However, Pikachu accidentally shocks Buizel and this causes them to argue which makes a difficulty in helping Ash defeat Wake. Suddenly, thanks to that Buizel had rescued Pikachu from the attack; their argument concludes. Ash manages to defeat Wake and he earns the Fen Badge.

When Ash & Co. are invited to attend a Pokémon Academy, they decide to enter it. For their first task, they choose a PokéBall that contains a Pokémon inside. The trainer then has to train the Pokémon and be able to use it in battle. The gang then meets Angie, and meets Conway again.

While at a Pokémon Academy, Ash, Dawn, Brock, Angie, and Conway find that their Pokémon are becoming hypnotized when they go near a lake. So they decide to go and investigate what's going on.

Dawn competes against Kenny in the Solaceon Town Contest, looking for redemption after her crushing loss in Hearthome City. Jessie of course enters. Dawn loses once again and Kenny and Jessie face-off in the finals. Jessie defeats Kenny and wins her first ribbon. Zoey tells Dawn that the overuse of Swift caused Ambipom to be no longer seen and the point of an Appeal is to show off the Pokémon.

Ash, Brock and Dawn meet the Champion of the Hoenn Region, Wallace. He says he will be holding a Pokémon Contest and the winner receives a ribbon that can be used anywhere. The group spends the day with him, resulting in advice from Wallace for Dawn to play with her Pokémon more and for Ash to enter Buizel in the contest. At the end of the episode, Ash receives a phone call from his friend, May.

In Solaceon Town, Ash's group meets up with Dawn's old friend and rival Kenny and his new Pokémon, Breloom. Kenny tells them he is going to the Solaceon Ruins, a place of worship for the legendary Dialga and Palkia, so they tag along, only to get more than they bargained for when the Unown that live in the ruins become furious along with the appearance of the sinister Team Galactic. Among the chaos, Aipom evolves into Ambipom

Ash and company visit a town where it is plagued with a group of Gligar led by a Gliscor. Ash and friends help Officer Jenny try to remove the flying Pokémon, while Ash's rival Paul sets his eyes on capturing Gliscor. In the end, Paul captures the Gliscor on his team, and Ash captures one of the Gligar that keeps showing up.

Ash and his friends meet Sho, a boy who has a Pichu and a Raichu. He mistakes Ash's Pikachu for a wild Pokémon. Just like at the Vermillion City Gym, Ash and Pikachu have the option again to evolve Pikachu to Raichu, after a loss to a stronger opponent. Paul witnesses this defeat and scolds Ash for losing to such an opponent, but manages to redeem himself of that defeat in a rematch.

A Swinub shows up at Mr. Backlot's mansion and starts to eat all the Poffins. Dawn tries to stop it by making her own Poffins for Swinub. Dawn ends up capturing Swinub at the end of the episode.

While Ash and friends are training at the Summer Academy, they are taught how to deal with Ghost-Type Pokémon, should they ever run into them. They are then paired up to find a hidden treasure. While searching, Conway has a run-in with a Dusknoir.

Upon arriving at the Hearthome Gym, Ash and his friends run into Barry, a trainer from Twinleaf Town. Barry turns out to be an admirer of Paul, whom he saw when watching the Double Battle Tournament. Ash challenges Barry to a Pokémon battle. Ash chooses Chimchar, Gliscor, and Pikachu, against Barry's Staraptor, Roserade, and Empoleon. Ash manages to narrowly defeat Barry, finishing off Empoleon with Pikachu's Volt Tackle.

Buizel is more interested in Ash's gym training, and Aipom is more interested in Dawn's contest training. Thus, Zoey suggests that Ash and Dawn do a trade.

After the Trainers are finished with the training, they must use a Pokémon to bring them across a rigorous track to the finish line. Finally after a tough competition Ash and Pikachu came first, and Angie and Shinx came second which led to the victory of the red team. Everyone is given a certificate. They said good bye, and the team continued their journey.