After surprising everyone by choosing to face the Legendary Pokémon Articuno in his first Battle Frontier battle, Ash calls upon an old friend to battle it as he plans to use fire against ice. Will Ash be victorious in his first Battle Frontier battle.

The preliminaries are over and now the Hoenn League Championships begin in earnest. The qualifying round is all double battles and Ash goes to watch Morrison's match against muscleman Gavin.

Ash and May prepare for the challenge ahead of them in the Kanto region. May left two of her Pokémon with her parents at Petalburg City in Hoenn. However, before their new adventure, Team Rocket shows up to steal all of Ash's Pokémon and the group must fight to stop their dastardly plan. After stopping Team Rocket plans, May leaves one of her Pokémon with Professor Oak but a Squirtle chooses her as its Trainer and accepts it to her team. Ash also leaves two of his Pokémon he caught in Hoenn with Professor Oak as well but one of his from the lab decides to accompany him on his new journey.

Team Aqua has gained control over Kyogre and prepares to unleash its powers over the world's water levels. A Blue Orb-possessed Pikachu releases Groudon from its entrapment and the two prepare to take on Kyogre in a battle to end all battles. Will Groudon and Kyogre destroy the world with their legendary battle or will Lance, Ash and his friends be able to stop the world's imminent destruction?

The final battle for Ash's final badge continues as he has managed to beat Juan's Sealeo and Seaking. Now he must contend with the rest of his Pokémon, like Luvdisc who used Sweet Kiss to confuse Grovyle. With three Pokémon left against Juan's three, will Ash be able to win his final badge or will he be washed away with the tide?

Ash struggles against an opponent whose strategy is a marked contrast to his straightforward style and tries to throw her off with Corphish, one of his spunkiest Pokémon.

On his way home to Pallet Town after saying goodbye to his friends, Ash meets Scott, Leader of the Battle Frontier. After losing to Elite Four member Agatha, Scott tells Ash about the Battle Frontier. The latter agrees to take the challenge but first he must deal with Team Rocket and return to Pallet Town. After coming home, Ash meets up with his old traveling friend Misty.

The Battle Factory is Ash's next destination—if he can find it, that is. He and his friends have become lost, but they see snow and an Articuno flying overhead, followed by a plane in distress. The group winds up at a Pokémon Center, where Scott gives them a ride to the Battle Factory. There they meet Noland, who's not just the Factory Head but also a bit of a mechanical mastermind, and the pilot of the plane they saw last night. Ash can pick which of Noland's Pokémon he wants to battle. Noland has befriended an Articuno whom he helped once, and he takes Max and Pikachu up in his plane to fly with the Legendary Pokémon. Team Rocket wants Articuno for themselves, and they show up in their own plane to steal it. It's no match for Articuno, who quickly sends them on their way. Impressed, Ash decides he wants to battle Articuno. What's more, he wants to battle it with Charizard! It looks like this is shaping up to be quite a match...

Due to a twist of fate, the heroes get captured by Team Magma and face their leader, Maxie. After Maxie explained his goals, Team Aqua's Shelly frees Kyogre and reports to her leader. In a moment of confusion, Pikachu takes the Blue Orb, which gets absorbed into him. Just as the heroes try to escape, Ash gets captured, while Team Aqua's leader starts controlling Kyogre. However, an unexpected help arrives, a man whom Ash and Brock have met before.

May continues to take Harley's advice as she advances in the tournament. Drew, however, has his suspicions about Harley and continues to monitor him. Meanwhile, Ash and Max join forces with Officer Jenny to help a Coordinator, Anthony, whose ribbons and contest pass have been stolen.

Ash's new friend and rival arrives just in time to register for the Championships. Although, Tyson's Meowth has a strong showing as it displays uncharacteristic rage, even attacking its opponent after the battle.

With the Hoenn League still underway, Ash and Tyson battle it out to decide which one of them will move on to the final four. Since Glalie and Sceptile are already knocked out of the competition, who will get the upper hand?

Continuing across Izabe Island, Max finds a sick Ralts. Brock is unable to fully cure it and they must bring it to the Pokémon Center. However, Team Rocket wants to capture the Ralts. Ash, May, and Brock battle Team Rocket while Max rushes to the Pokémon Center as quick as can. However, he must get there before it is too late, and has to deal with Team Rocket again and also Kirlia and Gardevoir.

Ash begins his third battle in the qualifying round of the Hoenn League Championships and knows he's up for a challenge. After getting three victorious in the qualifying round, Ash and his new friends ascend to the victory tournament. In his first victory tournament match, Ash goes up against a trainer famous for her keen strategy.

Ash faces his off against newfound friend and rival, Morrison. However, Ash knows how to put friendship aside in battle while Morrison does not and the less experienced trainer is hesitating to battle against him. Will Morrison pull himself together and gives his all against Ash or will the match end in his favor.

Still heading for Cerosi Town and the ferry to Sootopolis City, Ash and his friends stop at a Pokémon Center to stay warm as a blizzard approaches. At the Center, a wild Snorunt steals all 7 of Ash’s Badges. Will he be able to get them back or will he have to train all over again?

The final battle is approaching, Gym Battle that is. Ash and co. arrive in Sootopolis City, home of Ash's final Gym Battle. There they meet Juan, who is not only the Gym Leader but a Grand Festival winner as well. Does Ash have what it takes to beat an accomplished trainer like Juan?

The heroes arrive at Ever Grande City, the site of the Hoenn League. On May's request, they go around town for a noodle shop, but end up getting assaulted by a group of Murkrow. In that moment, a Meowth, wearing a hat and boots, attacks the Murkrow and disperses them. Its trainer, Tyson, greets the group, and adds that he is also a participant of the League. Moreover, he is also a torchbearer of the Moltres flame, which Team Rocket intends on stealing.

Ash and his friends set out for Mt. Moon, home to the Cleffa family of Pokémon. However, the young Trainers are surprised when they spot a lone, distraught Cleffa.

May has arrived in Slateport City for the Grand Festival. Her mother, Caroline, has come to cheer her on, and her friends sent notes to wish her luck. With 247 competitors in the preliminary matches and only 64 slots in the main competition round, May will need more than just luck—especially when Drew and Harley are among the competitors, too! Harley is friendly towards May, but her friends are suspicious of the advice he gives her. Meanwhile, Team Rocket has dressed James up as Norman and offers free counseling sessions. When Trainers show up, their Pokémon are stolen! Harley sees this and drags May off to see "Norman." When she and her friends see the false Norman, Team Rocket's number is up. With Team Rocket's plan foiled, it's back to the competition. May uses Silver Wind just as Harley suggested, and it works great. She advances to the next round along with Harley and Drew. But Drew is still skeptical of Harley's motives as they prepare for the main competition.

Once again, the time has come. Ash will have a double battle against the terrific twins, Tate and Liza. As the battle begins, he sees they don't get along very well and the battle could be an easy win for him. That is, until Team Rocket interferes and snatches Lunatone and Solrock. After thwarting their latest plot, Rachel suggest that Ash and Liza and Tate continue their battle, even though the Gym is destroyed they could have it on the cliff. As the rematch begins, Liza and Tate are more in-sync than ever. Will Ash be able to beat them this time? The answer might shock you.

After battling a trainer, Ash, as well as his friends, meet Drake of the Elite Four. Drake is impressed by Ash's skills and invites the heroes to his boat, where Ash will have a battle with him. Just as everyone sees Drake doesn't do much, the latter makes his counterattack and shows Ash where he went wrong.

As the heroes sail to May's next Contest, May finds a boy named Harley. She speaks to him a bit and meets his Cacturne and eats his cookies. Harley is annoyed at the girl, who becomes his rival that he wants to crush. During the Contest, Harley gives May some false advice, which May accepts, only to find out Harley tricked her. Just as she faces Harley, he uses another trick up his sleeve to deceive May even more, wanting her to be defeated.

While on their journey across Izabe Island, Ash and his friends meet a girl named Samantha, who performs her ribbon dance in various towns, and her Mawile, who develops a crush on Brock's Lombre. In the next town, Team Rocket takes Mawile, but ends up taking Lombre by mistake. Now Ash and his friends must save Lombre and Samantha's show.

On their way to the Grand Festival, the gang stops on an island filled with Berries. May decides to make Pokéblocks, but no one except a wild Munchlax likes it. When Munchlax is blamed of eating everyone's Pokéblocks, May decides to prove them wrong and capture Munchlax.