After Ash's victory at the Laverre Gym, our heroes are walking with Sawyer, who’s completely focused on his battle notebook and not watching where he’s going—until he trips and falls, dropping his notebook in the process! He doesn’t realize this until later, and by that time, Team Rocket has picked it up, determined to make use of all the information within. With the help of his Slurpuff’s talented nose, Sawyer manages to track down his prized possession, and he and Ash battle together to send Team Rocket blasting off again. Then, they decide to battle against each other!
Ash seems to be firmly in command...until Sawyer’s Treecko evolves into Grovyle and presents Frogadier with quite a challenge! Frogadier pulls off the win, but it’s a close one, and afterward, it’s clear that the two Pokémon are itching for a rematch. Sawyer heads off to challenge the Coumarine Gym, while Serena has her eye on the Pokémon Showcase in Dendemille Town, on the way to Ash’s next Gym battle in Anistar City!
Following Ash's win at the Laverre City Gym, he and his friends, accompanied by Sawyer, head away from the Gym. However, Sawyer trips along the way and as he gets up, he drops his notebook, which is promptly found by Meowth. As soon as Jessie, James, and Meowth look inside the notebook, they see a photograph of Steven Stone, and James instantly recognizes him as the Champion in the Hoenn region. Meanwhile, Serena treats the group to lots of sweets and Poké Puffs after Ash's hard-earned victory over Valerie. Sawyer expresses his awe of Ash's battling style to him, and Ash reminds him that it was due to the Pokémon's efforts that they won the Fairy Badge.
However, at that moment, Sawyer notices that his notebook is gone. He goes into a panic, suddenly remembering that he dropped it where he had tripped earlier. Jessie, James, and Meowth, who still have the notebook, have mistakenly come to the conclusion that it belongs to Steven himself. While James and Meowth are more interested in learning the "Champion's" techniques, Jessie is immediately enamored with him and begins deluding herself with fantasies of someday marrying into his family so that she can be part of the Devon Corporation. Meanwhile, Ash and company, having returned to the bridge where Sawyer's notebook disappears, agree to split up and search for it individually. Later, at the Pokémon Center, they all report having seen no trace of it anywhere. Sawyer tells them how he kept taking notes after every battle he and Treecko had, and they kept getting stronger together, and he also mentions his meeting with Steven Stone and all of the valuable advice Steven gave him.
Bonnie asks Clemont for an invention to help find the notebook, but Clemont starts to explain that he doesn't even have something like the notebook's smell to work with. Suddenly, Sawyer jumps up in excitement and calls out his Slurpuff to help search for the notebook using its keen sense of smell. With direction from Treecko, Slurpuff races away to try and locate the notebook. James is still poring over its contents, unaware that they were written by a novice Trainer, when Slurpuff arrives. Slurpuff takes the notebook and runs off with it, chased by Team Rocket, and returns it to Sawyer. When Team Rocket arrives, everyone realizes that they were the ones who stole the notebook. Sawyer quickly corrects them when they refer to it as the Champion's notebook by pointing out Steven's autograph. Angered by this news, Jessie and James decide to fall back on their usual plan of stealing the group's Pokémon. Jessie calls out her Pumpkaboo and James his Inkay to face Sawyer's Treecko and Ash's Pikachu. The battle is short-lived—as attacks from each of the four Pokémon cancel each other out, Pikachu uses another Thunderbolt and easily sends Team Rocket blasting off.
That night, Serena learns of a Pokémon Showcase being held in the nearby Dendemille Town and decides to register for it. She then informs Ash, using her Town Map, that Dendemille Town is also on the way to a city with a Gym—Anistar City, where he agrees to go for his seventh Badge. Sawyer informs the group that he plans on heading to Coumarine City to try and earn a Plant Badge. The next morning, Sawyer requests a three-on-three battle with Ash to make up for the one that they never finished. The first match is Pikachu against Sawyer's Bagon. Pikachu begins with Quick Attack, overpowering Bagon's Headbutt with superior speed. After a collision of Dragon Breath and Thunderbolt, Pikachu breaks through Dragon Claw with an Iron Tail attack to defeat Bagon and win the first round. The second match is then decided to be Slurpuff against Hawlucha. Although Slurpuff uses Electro Ball, a super effective move, Hawlucha dodges and strikes back with Karate Chop. However, Sawyer becomes distracted checking his notebook and fails to notice Hawlucha's Flying Press, resulting in Slurpuff's defeat.
Ash calls to Sawyer, reminding him to stay calm during a battle, because the Pokémon will feel the same way as the Trainer during a match. Sawyer remembers Ash's Gym battle and sees the truth in Ash's advice, bringing out his Treecko to battle against Frogadier. Sawyer is momentarily caught off-guard by Frogadier's use of Aerial Ace, but he recovers and Treecko strikes back with repeated Bullet Seed attacks. As Frogadier manages to evade most of them, Sawyer remembers to stay calm and Treecko uses Agility. Despite the boost in speed, however, Treecko is still struck by Frogadier's Water Pulse. In response, Treecko evolves into Grovyle, and Ash tells Sawyer that Treecko evolved because of his feelings. Sawyer uses Grovyle's new move, Leaf Blade, to counter Double Team, but Frogadier still manages to get the better of Grovyle with another Aerial Ace. The two Pokémon continue trading and dodging attacks at high speeds, but thanks to a surprise attack by Frogadier at the very end, Grovyle is knocked out and the final round goes to Ash as well. Everyone notices Grovyle's newfound rivalry with Frogadier, and Sawyer and Grovyle are more determined than ever to get stronger and challenge Ash to a rematch someday.