The kids finally arrive in Lilycove City, and Ash is starving. They decide to head to a restaurant that serves omelets, but Pikachu runs off, leading them to the berry market. In the berry market, they meet a Pokémon Coordinator named Kelly and her Grumpig. Kelly is buying berries to make PokéBlocks with, and she plans to enter the Lilycove Pokémon Contest. Kelly invites them to her home, which is attached to a PokéBlock store that her mother runs. Kelly's mom teaches May and Brock how to make PokéBlocks in the Berry Blender.
Ash wants to teach Swellow the move Aerial Ace before his next Gym battle, so he ventures outside with Max to practice. They meet an old man named Ralph, who was once known as "Vladimir the Attacker," a famous Pokémon Trainer. He offers to help.
May makes her first PokéBlocks and tests them on her Pokémon, but only Beautifly likes them. Team Rocket shows up and tries to steal Kelly's Grumpig, but May has Combusken use Sky Uppercut to send them blasting off. After Kelly compliments the Fire- and Fighting-type Pokémon, May decides to use Combusken in the Lilycove Contest.
When Team Rocket finally hits the ground, Jessie finds a flyer for the contest and decides to enter with James' Chimecho.
The contest begins, and May is called up first. She starts by having Combusken perform Fire Spin, but it goes out of control...
Ash and his friends have finally reached Lilycove City. As Ash and Pikachu collapse from missing lunch, May checks her guidebook describing all the restaurants in Lilycove. Then a poster on a nearby wall catches her eye: the city is holding a Pokémon Contest tomorrow. May decides to enter, so the group searches for a place for her to train. As they continue walking, Pikachu's expression changes suddenly; he becomes very excited and runs off. Ash and company chase the little Pokémon and they arrive at Lilycove's famous Berry market, and they’re excited by the wide variety on offer. Before they can buy any Berries, they all notice a girl with a Grumpig nearby and she seems very frustrated. She is trying to haggle with the man at the Berry stand. A man approaches them and offers free samples. He offers Pikachu some slices of Nomel Berries, which Pikachu happily gobbles up. Ash, also hungry, grabs a slice, but the Nomel Berry proves too sour. The vendor explains that Nomel Berries are much better for Pokémon and then he offers Ash some sweet tasting Mago Berries. Suddenly, Ash notices the young girl with a Grumpig walking by, carrying her heavy grocery bag. She trips over, and as her groceries spill out Grumpig uses a Psychic attack to avoid calamity. Everyone begins clapping for Grumpig, and the girl thanks them for the applause admitting they are hoping for the best in the upcoming Contest. May is surprised and introduces herself to the girl, who says that her name is Kelly, a fellow Pokémon Coordinator. Ash does a Pokédex data check on Grumpig. Naturally, Team Rocket have also witnesses Grumpig's heroics and have decided to make Grumpig their next acquisition.
Later on, Ash and his friends hang out with Kelly and Grumpig at a nearby park bench. May notices the sheen of Grumpig’s black pearls, and Kelly explains that the Berries she bought keep Grumpig looking great. Brock is certainly impressed to see such a pro Coordinator, with Pokéblocks and all. Max is wondering how many Ribbons she's got, but then May sharply reminds him that she's there too. Kelly is also curious, as May reluctantly shows off her two Ribbons, Kelly is greatly impressed, as she only has one. Suddenly, as Kelly mentions that she’s eager to win the Lilycove Ribbon, the two exchange tough words, igniting a rivalry. Meanwhile, Brock is looking at the guidebook for a place to eat, and as soon as Kelly notices, she swipes it from his hand. Before he can take it back, she says most of the places in that book are old, and she has a perfect idea for restaurant – her home and mother's Pokéblock shop.
As they enter the store, they find themselves face to face with shelves stacked with Pokéblocks. Kelly calls her mother down, introduces her new friends, asking to treat them to dinner. At the table, Otane serves them some fresh Lilycove stew, which everyone eagerly digs into. After the meal, Kelly offers to teach May and the others how to make Pokéblocks. Everyone seems to be all excited and ready to give it a shot, except Ash, who just remembered something. Ever since battling Winona back at Fortree Gym, he had been meaning to find an opportunity to train with his Swellow and teach it the move Aerial Ace. While May and others learn to Pokéblocks, Ash leaves to train Swellow. After Otane explains how to operate a Berry Blender, Max decides to check on Ash’s progress.
Ash orders Swellow to fly up into the air and soon after, has it dive down towards a stick hanging from the tree. However Swellow loses control and hits the ground headfirst with a thud, getting its beak stuck in the ground. As Max arrives, Ash decides to call it a day and head back, just when an old man appears, chuckling at them. The boys are left in awe as the man introduces himself as Vladimir the Attacker, so they and Swellow beg for his expertise. Vladimir gladly accepts, but it will take a lot of work and practice. Vladimir takes Ash and Max to his training field, where he will demonstrates the movements of Aerial Ace with his Pidgeotto. The three steps are starting off with a steep dive, level off at the last second and thirdly use ground effect for speed. After adjusting the bar to a perfect height for a beginner like Swellow, Ash lets Swellow try Aerial Ace. Seeing as the bar is pretty high, Swellow easily passes underneath. However, slowly, they move the bar lower and lower each time, Swellow succeeding to limbo under it every time. Eventually it reaches two feet, which is the proper Aerial Ace distance from the ground. As Swellow tries this one, it loses control and lands with a thud. However it returns to the skies, with its resilience impressing Vladimir.
As May chops up her Berries, she dumps them in a blender and pushes a button. Kelly explains that each button has a different effect, and the number field signifies the Pokéblock level. After it finishes, it stops at level 27, and out come some LiteBlue Pokéblocks. Kelly then congratulates May, but a taste test reveals that its flavor is weak. May samples one, and makes a disgusted face. Kelly adds that she sometimes uses up to 11 different Berries to get the right flavor, and that it is a good idea to record which combinations have been whipped up. May shrieks, admitting that she forgot to record anything down. Outside, May gives her four Pokémon a dose of her homemade Pokéblocks, with Beautifly getting it as Pokéblock juice. Unfortunately for her, only Beautifly seems to enjoy the taste. May sighs in disappointment, but Kelly reminds her that experimentation is all part of Pokéblock making. Kelly declares that her dream is to one day take over the shop and run Pokéblock making classes. As she asks May about her intentions, May admits that she is enjoying traveling at the moment and has no long-term ambitions even as a Coordinator. Kelly realizes May’s point, explaining that there is no need to rush into the future, especially with a lot of learning left to do. May hesitantly wishes her luck, but rivals are rivals, and she intends to win this one. Kelly wishes May luck, getting ready to go home.
Before Kelly takes a step, a huge claw came out of nowhere and grabs Grumpig. While Grumpig tries to squirm free, May has Combusken jump up and use Sky Uppercut on the balloon, knocking Team Rocket down and freeing Grumpig. To save Grumpig from suffering an injury, Bulbasaur grabs it with Vine Whip, placing it safely on the ground. Finally, Beautifly uses Silver Wind to blast Team Rocket off. Kelly thanks them, and notes that she was most impressed with Combusken's Sky Uppercut. This gives May the bright idea of entering Combusken into the Lilycove Contest. Team Rocket land in a dumpster and as they they scramble out, it tips over. Amid the garbage is a notice regarding tomorrow's Pokémon Contest. Jessie demands to borrow James's Chimecho, adding that a new Pokemon might bring her victory. She blackmails James into complying, reminding him that he used her Dustox in the "silly" Crossgate PokéRinger event.
The day of the Contest has come, and while Vivian makes her announcements and introduces the Contest Judges, the boys wait for May, but Ash is still eager to train with Swellow a bit more. Brock and Max don't seem to mind, so Ash gets up and heads outside. Meanwhile, James prays that Jessie will handle Chimecho well. May is in the waiting room, shooting the breeze with Kelly as they patiently wait for their turn. Jessie, in the corner, introduces herself to Chimecho and harshly demands that it win her the Contest or else. In the Appeals Round, May is the first up. Ash and Swellow pause their training and watch from the television screen outside. As she lets Combusken onto the stage, Vivian introduces it. May has Combusken use Fire Spin, but the flames quickly grow larger than expected. May hits the ground while the attack threatens to engulf her and the stage, the fate of the Contest seems to be up in the air.