It's finally the evening of the Sinnoh League opening ceremony. After seeing that his rivals have all managed to make it to the League, Ash learns that his first battle will be against Nando, the Pokémon minstrel who he and Dawn befriended early in their journey in Sinnoh.

Nando approaches Ash and the two talk about their upcoming match, then shake hands. Later, with help from Dawn and Brock, Ash works on a strategy to use against him. Recalling his battle in the Grand Festival with Zoey, Dawn mentions that Nando's Lopunny has a number of moves that can be used to dodge attacks. Paul walks past, but when Ash approaches him, he merely says that Ash will lose before the two can battle and walks off.

Team Rocket attends a seminar for the sellers operating sales booths at the tournament. They are frustrated to learn that their booth is far in a corner, away from the action.

Late that night, Ash awakens and walks to the balcony of his room, where he recalls each of his eight Gym battles in Sinnoh. The next morning, as the trio leaves the Pokémon Center, Ash runs into Barry, and Conway soon appears as well. Meanwhile, Team Rocket devise a plan to boost their sales.

Barry wins his first round match with ease, but as he leaves the arena he passes a mysterious man whose presence startles him.

Ash and Nando are introduced to the crowd, and their battle begins. With Cynthia and President Goodshow in attendance for the battle, Nando sends out Roserade while Ash sends out Staraptor. Brock notes Ash has a type advantage.

As soon as the referee officially starts the battle, Nando calls for Sweet Scent, which drops Staraptor to a lower altitude and stuns it. Before Ash can react, he orders Roserade to use Magical Leaf, which Staraptor cannot evade, sending it crashing to the ground. Finally, Nando completes his relentless attack by commanding SolarBeam. Roserade uses the attack, but Staraptor manages to escape from it just in time, and Roserade is defeated quickly by Staraptor's Brave Bird.

Humbled, Nando recalls Roserade and sends out Armaldo. Ash attempts to use Close Combat, but Nando has Armaldo block it with Protect before knocking out Staraptor with Rock Blast. With the match tied, Ash sends in Quilava. In the stands, Barry suddenly rushes up to Dawn and Brock and tells them about the creepy trainer he met, who he saw using a Darkrai in battle.

Meanwhile, Team Rocket has begun selling their wares outside of their approved stall space, which actually impresses their boss.

Back at the battle, both Armaldo and Quilava have become noticeably tired. Wishing to end the match decisively, Nando calls for X-Scissor, which Ash counters using Aerial Ace. The two Pokémon lock in combat for a brief time, then they both collapse, resulting in a tie. While Dawn, Brock and Barry discuss this turn of events, Conway suddenly appears again and introduces himself to Barry.

Nando sends out his Kricketune as his final Pokémon, while Ash settles on Heracross. Ash commands a Megahorn and Nando has Kricketune use Silver Wind, and the two attacks cancel each other out. Nando then calls for Sing, which puts Heracross to sleep, then Fury Cutter. Just before Kricketune's Fury Cutter hits, though, Ash tells Heracross to use Sleep Talk. Heracross, while not waking up, flies upward and hits Kricketune back with a Focus Punch.

Barry is stunned by this, and Conway explains that Sleep Talk randomly selects a move known by the Pokémon to use while it is asleep. Heracross wakes up, and Ash tells it to use Focus Punch again. Kricketune deftly dodges Heracross's repeated attacks, and Nando calls for Fury Cutter once more; the two exchange blows in a furious fight. Becoming flustered at Ash's persistence, Nando finally orders Kricketune to use Sing again. This gives Ash an opening, which he takes to order a Horn Attack; Heracross hits the ground in front of Kricketune and stuns it. Ash then commands a final Megahorn, and Heracross rips its horn upward through the ground under Kricketune's feet, sending it flying through the air, then crashing down to the ground. Kricketune faints, and Ash wins the battle.

Team Rocket's strategy has paid off, and their sales have increased dramatically. Their boss decides that she will give them a promotion to a better location.

After the match, Nando speaks to Ash and his friends outside the stadium. He wishes Ash luck in the rest of the tournament, then cheerfully departs for his next goal. Later, after Paul wins his first match, Brock remembers to tell Ash about the Darkrai trainer, who Ash quickly decides he would like to battle.