Da Ash ankommer til Littleroot Town, opdager han og Professor Birch, at Pikachu har en elektrisk overbelastning. Den overflødige elektrisitet resulterer i at Pikachu løber væk smerte, efterfulgt af Ash og Professor Birch. Snart efter blive Professor Birch jagtet af en flok Poochyena og må bede træneren May, som lige er startet på sin rejse, om hjælp. Den unge pige vælger en Torchic, som sin første Pokémon.

Ash og May finder nogle ruiner, hvor de hjælper Professor Aldon med at genopdage en næsten uddød Pokémon-art. Der har de også deres første møde med Team Magma.

Ash ankommer til Petalburg City, hvor han gerne vil have sin første styrkecenter-dyst. Ash møde Mays lillebror, Max. Norman, Mays far, er Petalburgs styrkecenter-leder, men han accepterer ikke Ashs udfordring, da Ash endnu ikke har tre Pokémon. De har en uformel dyst, som bliver afbrudt af Team Rocket.

Ash fanger sin første Pokémon, en Taillow, i Hoenn. Brock og hans Forretress vender tilbage.

En dreng ved navn Nicholai forsøger at fange en Zigzagoon. May har sin første dyst mod ham, efter han hører, at hun er styrkecenter-lederens datter. Da Nicholai fornærmer Mays far, ønske hendes lillebror Max hævn.

Team Rocket møder en krybskytte, som jager gift-Pokémon. Da Team Rocket finder ud af, at de indfangede Pokémon inkluderer Koffing og Ekans, beslutter de sig for at befrie dem fra krybskytten og derefter sætte deres Arbok og Weezing, så de kan beskytte dem. James fanger får til sidst en ny Pokémon: Cacnea.

En gruppe af Treecko beskytter et døende træ, og én af dem beslutter sig for at tage med Ash.

Ashs Treecko bliver slået af en vild Seviper. Mens at Treecko gør sig klar på en omkamp, har Jessie sat sig Seviper'en for øje.

Max møde en Shroomish i en gyde, som han bliver venner med.

Ash kæmper mod en træner og hans Pelipper, som kan bruge angreb, den ikke normalt kan lære.

Max tager sig af en Poochyena, så den kan udvikle sig og blive fri.

Ashs og hans venner for deres første glimt af en Pokémon-konkurrence.

Lamslået over Beautiflys optræden beslutter May sig for at fange en Wurmple, så hun kan få sin egen Beautifly.

Ash og hans venner ankommer til en træner-skole, som ledes of Roxanne, Rustboros styrkecenter-leder. Max deltager i en skoledyst mod en uhøflig dreng.

Ash og Roxanne udkæmper en styrkecenter-dyst, og May beslutter sig for at blive Pokémon-koordinator i stedet.

After winning the Stone Badge from Roxanne, Ash and co. head out to the next gym, located on Dewford Island. However, Max spills a drink on his PokéNav and rather than suffer her wrath, Max tries to find a quick solution. He sees an old man demonstrating new inventions but before he can go further, a younger man picks him up in a limo. Who is this old man, and can he help Max fix the PokéNav before May finds out it's broken?

May may be the new Misty but she is not as smart as she was. And she proves this when she, Ash, Brock and Max head to a pasta restaurant that May read up on the internet. The thing was May forgot to check the date and found that the place was closed. The date was exactly the same day, exactly the same month, ten years ago. Things go from bad to worse when they find the pier on the other side of town. May tries to find help and finds a kind sailor by the name of Mr. Briney. But when she returned with her friends, his personality changed for the worse. Could May have goofed up again? Or is someone else pulling Mr. Briney's strings?

After the incident with the Team Aqua agent and with Peeko safely returned to Mr. Briney, Ash and co set sail for Dewford Island. All is not calm on the way there however as a school of Sharpedo suddenly attack Mr. Briney's boat. Not to mention tear up a part of May's new swimsuit. Now how will Ash and co. get to Dewford with all the Sharpedo in the way? Is this going to be like "Jaws" all over again?

After a night at the Pokémon center, Ash is stoked to have another Gym Battle. He meets the Gym Leader Brawly, who would rather surf than battle, which infuriates Ash. Could there be more to this Gym Leader than meets the eye? And does May even have a shred of decency?

After being beaten by Brawly, Ash decides to stay at Dewford Island and do some serious training of one thing he lacks: patience. He does this by practicing the fine art of Fishing. He, along with May, Max and Brock, accidentally hook Team Rocket's Magikarp submarine and after a fierce battle, May notices something different about her Wurmple: it is actually Jessie's. Can the heroes find May's Wurmple before Team Rocket figures it out?

While exploring Dewford Island, Ash and friends notice a large cave and Max states that it's Granite Cave. They all enter and soon they fall into a pit trap courtesy of Team Rocket. Unfortunately, they fall in as well and the two groups are mixed and separated. This time around, there are three groups: Males being Ash, Brock and James. Females being May and Jessie and the rest being Max, Pikachu and Meowth. Can these groups be brought back to order and who is in Granite Cave along with our heroes and villains?

A mysterious Pokémon is terrorizing Dewford Town's beach. Ash and friends set many traps for the terror and discover its identity, Corphish. Will Ash and his friends be able to capture the feisty Water-type Pokémon, or will it set them out to dry?

With a new Pokémon in tow, Ash continues his training to prepare for his rematch with Brawly. However, Corphish is still a ruffian as it introduced itself by whacking all the other Pokémon on the head. Can it ever be more social with other Pokémon, and why is Jessie's Silcoon purple right after it evolved?

Get ready for a new episode of May's Expedition as she, Ash, Max and Brock stumble upon a swamp. There they find a swamp full on Mudkip and their caretaker, an elderly man named Old Man Swamp (or Mr. Swampy) who has the same whiskers as a Mudkip's fins. He explains that he gets Mudkip eggs from the Hoenn League and when they hatch they wait until they're old enough to give to Professor Birch. But Team Rocket also has plans for the Mudkip. What evil will they have in store for them, and will Brock get a new friend?

While Ash preps up for his rematch with Brawly, Corphish pinches the ears of a Loudred, causing it to scream. Corphish, along with Pikachu, Silcoon, Torchic, Lotad and Mudkip get lost and soon they encounter a tribe of Nuzleaf. Can Ash and co. find their Pokémon before it's too late?

As Ash continues his training, he, May, Max and Brock encounter Prof. Birch. Meanwhile, a boy's Nincada was captured by Team Rocket and it digs a hole to a temple. There they encounter the commanders of the teams they encountered before: Team Magma's Harland and Team Aqua's Isabel. How will this clash of Aqua vs. Magma go down, and can Ash and co. help the boy save his Nincada?

After the ordeal in the last episode, Ash and co. continue training and are joined by Prof. Birch. May is so happy that her Silcoon will soon evolve. Elsewhere, Jessie is still in denial of the fact that her "Silcoon" is really a Cascoon. After a fierce battle, Silcoon evolves into Beautifly and blows away Team Rocket with a Gust attack. How will Jessie get her "Silcoon" to evolve and how will she take it if it doesn't evolve into what she wanted?

Corphish's bad attitude is showing no signs of improving so Ash plans to humble it a bit by putting a good scare into it deep inside an abandoned mine. Later on, Team Rocket discovers an abandoned gold mine and goes in. Can Ash and co. brave this mine in order to be well prepared for his rematch with Brawly?

As Ash prepares for his rematch with Brawly, he, May, Max and Brock meet a Battle Girl by the name of Shauna, whose reason for battling was to prove she was better than Ash. During their battle, Brock noticed that while Ash's training is paying off Shauna battled like Ash used to. Just as the match was about to be decided Brawly appears with some mondo bad news: A hurricane was approaching which could wipe out the beach. Can our heroes manage to weather the storm, and why is Shauna so nervous around Brawly?

It is time for Ash to have his rematch with Brawly. He decides to shake things up a little by using his new Corphish instead of Taillow on a new battlefield. With all the training Ash had to do up to this point, does he have what it takes to beat Brawly, or will he wipe out again and let it be all for nothing?

On their way to May's first contest in Slateport City, Ash and gang travel across the sea on a motorboat. After Team Rocket fails in their latest attempt to steal Ash's Pikachu, the boat stops working. Drifting along, they spot a large, abandoned ship and decide to go inside upon seeing a smaller boat off to the side.

Inside, they meet up with Tommy, a trainer who lost his Marshtomp on the ship long ago. He promises to give Ash and company a lift after he is done searching. Several Pokémon start to go missing and soon May, Max and Team Rocket are captured too. A Swampert and a Spinarak reveal themselves as the culprits.

Ash, Brock, Pikachu and Tommy soon come across the Swampert and Tommy recognizes the Swampert as his Marshtomp, but it retreats further into the ship. After saving the others, Tommy reunites with his lost friend and apologizes for leaving it behind. After thwarting another of Team Rocket's schemes, Ash and company leave on Tommy's boat for Slateport.

After arriving in Slateport City, May begins her training for the Contest. However, just as she and Beautifly have some good results, a boy named Drew appears and starts belittling May. May does not give up and has a battle with Ash. Despite losing, a man named Mr. Big appears and teaches May about Contests. He takes them to the shop, where he finds May's Torchic had eaten his Bluk Berry, which is to be used in tonight's firework event. In order to make amends, May goes with her friends in search for the berry.

May is eagerly preparing her Beautifly for the Pokémon Contest while Max watches her Torchic. He is debating which Pokémon he will begin with when he comes of age. May discovers a beached Wailord and contacts Nurse Joy at the Pokémon Center. Joy and Brock rush to help while Ash and Max are left to take care of the Pokémon Center.

Team Rocket decides to try to steal the Wailord. At the Pokémon Center, Ash, Max and all the Pokémon are having a difficult time capturing a particularly troublesome Torchic. The Torchic evolves into a Combusken, which is an even bigger headache, especially because a new Trainer is coming to choose between a Torchic, Mudkip, or Treecko. Team Rocket tries to steal Wailord, but the newly evolved Combusken foils their plans and sends them blasting off again. The new Trainer chooses Mudkip and Combusken is invited to stay and guard the Pokémon Center.

May enters Beautifly in the beauty contest, but Team Rocket is too late to enter their Dustox. At the competitions, the person in line right before May is none other than her rival Drew. Drew's Roselia gives an excellent performance, netting him an extremely high score. May is more determined than ever to beat Drew.

Meanwhile, Team Rocket is busy holding a "charity drive" scam for PokéBlocks. A little old man stops to talk to them about PokéBlocks. The contest is heating up with a Milotic stealing the show. May is up again in the contest and she and her Beautifly toss a disc back and forth, like they practiced before.

In the next round, she has to battle Drew who defeats her. He then looses to the contestant with the Milotic. May and Drew part on good terms and the scene ends with the old man still intently talking to a slumbering Team Rocket about PokéBlocks.

While Brock and May go shopping, Ash and Max go to the museum, only to find it closed. Max attempts to go in, but is caught by a boy, who claims they are thieves. Just then, Captain Stern arrives and the confusion is settled. While Ash and Max visit the exhibition, the members of Team Magma try to infiltrate the museum to steal Captain Stern's stone he recently acquired.

Oh no! Brock's worst fear has come to pass: A Pokemon Center without a Nurse Joy! IT'S THE END OF THE WORLD! (Well, not really.) But Ash and co. did find that strange. Who or what could be behind such a heinous deed, and why?

Continuing their journey to Mauville City, Ash and co. are starting to get lost by heavy fog. After Team Rocket got taken care of, they notice a lighthouse in the distance by two people and how does it work?

As Ash and co. are a mere stone throw away from Mauville City, they soon notice a poster for the House of Tricks. Anyone who navigates this wacky maze will receive a grand prize of a year's supply of Pokéblock. Along the way, May meets a cute Jigglypuff, but Ash and Brock remember it all too well. Can anyone listen to its song all the way through?

The time has come, once again. Ash was super psyched to have another Gym Battle. This time, it was with the elderly, yet hilarious, Wattson. The battle was short as Ash's Pikachu took out Wattson's entire team with just one hit each. Devastated, Wattson gave Ash the Dynamo Badge. Will Wattson recover from this, and what has happened to Pikachu?