When last seen, Ash is shocked to learn that his first-round opponent in the Victory Tournament will be against Gary, his eternal rival. After exchanging trash-talk, among which involved a half of a Poké Ball, Ash is enraged at the notion of Gary threatening to sweep him at the tournament. That night, back in his suite, Ash rummages through his backpack to find the other half (the smaller white half) of the Poké Ball, and proceeds to tell Misty and Brock his story of how the two of them had ended up with the halves of the ball:
It had been a few days before Ash first left to start his journey as a Pokémon Trainer. Fishing by a stream, he manages to catch a Magikarp, which proceeds to slap him in the face before falling back into the water. Gary, on the other side of the stream, appears to taunt Ash in both his skills and knowledge of Pokémon (Ash being unable to name any of Magikarp's attacks, including the Flail that was used on him, and Gary says Magikarp is the weakest Pokémon). The two had liked the stream as a fishing spot, and the rivalry escalates to the point that both Trainers are fishing in the same spot (but from opposite banks). When both Ash and Gary catch a bite, both reel their lines in, but discover that both had caught onto the same rusted Poké Ball. After a brief tug-of-war, the Poké Ball breaks in half. Though Ash was willing to accept that the "fishing battle" was a draw, Gary had declared it a loss, as "tying with Ash was just as bad as losing" - a position that he held to this very day.
Ash had kept his half of the Poké Ball as a good luck charm. He admits that losing to Gary and Eevee had taught him that he wasn't ready to take him on at the time, but he is prepared for the upcoming match. Though Ash is ready to battle Gary the next day, Misty reminds him that the next day is a rest day, with the Victory Tournament starting on the day after. Brock advises Ash to use that day to prepare his strategy.
The next day, Team Rocket reopens their new larger souvenir stand. Though Meowth tells Jessie that business may not pick up due to it being the rest day, James is confident that he could drum up business by holding a one-day sale of limited edition collector's pins, to appeal to the collector's market. Meanwhile, back in the suite, Misty is surprised to learn that Ash and Brock had buried themselves in books, preparing his strategy. Ash, for one, has not slept since the last night (Brock, however, had), though Brock is quick to point out that Ash is not as computer-literate as either himself or Misty. Ash, however, has managed to get a page up on Gary, showing data on ten of his Pokémon. However, just as he is trying to demonstrate to Misty on his computer skills, the computer crashes. Misty takes the opportunity to get Ash off the computer desk for breakfast.
Outside, Ash and company are discussing strategy. Brock notes that Gary has no particular type preference, just like his grandfather, and that he keeps rotating his Pokémon. Ash confirms this, and says that he has been that way for as long as he has known him. As Brock reaffirms that his team-building strategy will be crucial, Ash sees a shadow flying overhead. Once again, the Flamethrower greeting is a dead giveaway that it is Charizard, having arrived from Charicific Valley after a late-night request to Liza by Brock. Just as Ash is greeting Charizard, Gary appears. After a brief greeting, the two stare each other down until Professor Oak appears to break the silence, surprising both. Delia also appears, herself and Professor Oak having arrived to watch the Silver Conference live instead of on TV. Professor Oak advises the two to lighten up before moving onto other matters: having received a lot of new Pokémon data, Professor Oak updates the Pokédexes for both Ash and Gary. Though Misty and Brock are excited about the new Pokédex data and what they can learn from it, Gary stares at his Pokédex intently before leaving. Misty and Brock also remind Ash to prepare their strategy, so they, too, also leave, but not before Delia gives Ash some encouraging words.
Later that day, Meowth and Jessie congratulate themselves for selling out their merchandise yet again, thanks to the Trainers that did not advance to the Victory Tournament also buying their pins. James, however, is working even harder, as he adjusts his new machines to make 3000 new commemorative badges just to make the demand for the next day.
The next day, the Victory Tournament begins in earnest. Macy and Jackson are seen watching from the stands as the announcers explain the Victory Tournament: a full six-on-six battle with a random selection of battlefields (between grass, water, rock, and ice-based fields). In the round's opening match, Harrison easily advances when his Sneasel defeats a Machamp. Back in the locker rooms, Ash congratulates Harrison on his victory, and reminds him that he will square off against the winner between Ash and Gary in the quarterfinal round. Back on the field, Misty and Brock have already been seated, with Pikachu, Togepi, Politoed, and Psyduck ready to cheer Ash on. However, Gary has also brought his cheerleaders to cheer him on. As the announcer makes note of Gary being Professor Oak's grandson and Ash reaching the round of 16 at the Indigo Plateau, the match begins on the rock field, with Gary making the first move.
Gary leads off with Nidoqueen, while Ash leads off with Tauros. Nidoqueen starts with a super-effective Rock Smash that sends rocks flying into the air and causing Tauros damage. But he manages to push through the oncoming rocks and heads for Nidoqueen with a Horn Attack. But Nidoqueen blocks Tauros by catching his horns and then launches a Hyper Beam, easily knocking Tauros out of the match.
Ash sends out Heracross as his second Pokémon, and Gary pulls Nidoqueen for Magmar. Magmar begins with a Flamethrower, but Heracross evades the attack and connects with Fury Attack (incorrectly referred to as Fury Swipes). This sends Magmar straight up, allowing it to use Fire Blast. Magmar catches up to the falling Fire Blast and lands on Heracross, causing it massive damage. Adding insult to injury, Magmar also adds a point-blank Flamethrower to cripple Heracross. Suddenly, Heracross manages to blow the fire away with his wings and charges Magmar with a Megahorn, which overpowers Magmar's Flamethrower defense, knocking it out.
Unfazed, Gary sends out Blastoise - the final form of his starter, and the most powerful Pokémon on his team. Heracross starts with Fury Swipes, but Blastoise responds with Hydro Pump. Who will come out on top of that attack, and who will win?