As the sun shines down, Wigglytuff was setting up Pokémon balloons, Lombre was setting up Pokémon masks, Mudkip was setting up drinks, Snorunt was making ice cream, and Swablu was making Pokémon prize bags for stands at the festival. Pikachu, Plusle, and Minun run on the beach and stop to see the Pokémon festival which also has a large stage in the middle. They are happy to be at a festival. While Corphish was running a banana stand, a Snorlax walks up and eats all of the bananas which angers Corphish. After eating all of the bananas, Snorlax lands on top of Corphish and falls asleep. Corphish was able to squeeze out from under Snorlax. Whismur, Combusken, Pikachu, Torkoal, Forretress, Beautifly, and Bulbasaur were setting up the big stage. Plusle and Minun swing on what looks like a swing attached to the stage. Pikachu tells them to stop, but they fall off and land on top of him. Grovyle rolls a big board with an Azumarill on to the stage.
Elsewhere, Meowth, Wobbuffet, and Azumarill were riding in a car going down the road with Wobbuffet driving. They were headed towards the Summer Festival for Azumarill to perform. Meowth imagines making a lot of money in the city with Azumarill's act. Meowth blushes just thinking about the idea when the car's engine blows out. Pikachu, Plusle, and Minun are awaiting the arrival of Azumarill, but it's taking longer than expected for it to arrive. They run down the road to check what's taking so long. Meowth and his friends push the broken car down the road, while Azumarill refuses to get out and help. They meet up with each other, and Plusle and Minun are glad to have found Azumarill.
Out of nowhere, a Skarmory comes out of the sky, snatches Azumarill, and flies away. Plusle, Minun, and Pikachu use Thunderbolt to try to bring the Skarmory and Azumarill back down, but they land in the middle of the festival and send a lot of the fruit flying into the air. The fruit is eaten by Snorlax, and it falls asleep. Corphish steps in to try to stop Skarmory, but it knocks Corphish out. Bulbasaur uses Vine Whip to try to wake up Corphish. Grovyle uses Bullet Seed and Combusken uses Fire Spin to try to stop the Skarmory, but it still flies away to another island on the other side of the ocean. A very old Bellsprout approaches the other Pokémon and explains that there is a very important reason that Skarmory took Azumarill across the ocean to the other island.
Skarmory takes Azumarill into a cave on the island, where an Aggron approaches making Azumarill very scared. Bellsprout continues to explain the reasoning for Skarmory to take Azumarill over to the other island. Meowth yells at Pikachu and Grovyle is forced to break it up. The Pokémon decide to take a boat to the other island with Corphish pulling the boat the whole way there. As they are headed there, a Sharpedo's fin is shown swimming by. The Sharpedo move up closer to the boat as the boat tries to move faster. Sharpedo prepares to use Crunch while Combusken tries Fire Spin to send it away, but it fails. Sharpedo uses Crunch to break the boat, as all of the Sharpedo surround the boat. Plusle and Minun shock them with Thunderbolt, and Grovyle uses Bullet Seed to send the Sharpedo flying.
Corphish throws the rope so that the boat can quickly continue to the island. Sharpedo continue to go after them. Corphish uses Crabhammer and Grovyle uses Leaf Blade to create a big wave so the Sharpedo won't move any closer. Once they are on the island, the Pokémon realize that where they have to go is the very top of the mountain. They climb the pathway to get to the top of the mountain. Meowth slips as a rock breaks from underneath him, but the other Pokémon save him from falling to the ground. The Skarmory from before swoops in and tries to attack them. Combusken uses Flamethrower to send it away. Skarmory returns, and Combusken decides to stay behind and keep Skarmory from following the other Pokémon.
The Pokémon walk into the cave, with Meowth, Wobbuffet, Plusle, and Minun racing each other to see who could get to end first while Pikachu is not amused. Pikachu catches up with them as a Magnemite sees them enter the cave. Grovyle and Corphish head towards the incoming Sharpedo to attack. The Sharpedo use Hyper Beam, while Corphish uses Bubble Beam and Grovyle uses Bullet seed to counter it. Pikachu, Meowth, and the other Pokémon reach two different paths to continue on. Aggron and Magnemite approach them, and Aggron begins to attack them. Aggron yells very loudly, knocking the Pokémon backwards. Aggron uses Iron Tail while Pikachu knocks Aggron down with Thunderbolt. Meowth and Wobbuffet run and take the path on the right, with Magnemite following close behind them. Aggron stomps down, while Pikachu, Plusle, and Minun stomp down on the ground as well. The old Bellsprout asks Swellow to go and see what's going on at the island. Magnemite uses Thunder Wave while Wobbuffet uses Counter to send it back to hit Magnemite against the wall. Meowth and Wobbuffet go further down the pathway.
Meanwhile, Combusken is leading Skarmory away from the other Pokémon. Skarmory uses Swift, while Combusken counters with Sky Uppercut as they both fall down the cliff. Aggron tries to crush Pikachu, Plusle, and Minun with its claw, but instead the impact with the ground sends them flying into the wall. Aggron tries to come at them again, with Pikachu trying to protect Plusle and Minun. Grovyle uses Bullet Seed, Corphish uses Bubble Beam, and Combusken uses Fire Spin together to hit and knock down Aggron. Aggron gets up and Pikachu prepares to attack, but Meowth and Wobbuffet step in to stop the fighting. Aron, Lairon, and Azumarill arrive as the Aron and Lairon show affection to the Azumarill.
Aggron explains to the Pokémon that they would love to see the show, but they cannot go across the ocean to reach the other island. They heard about Azumarill through a conversation that a couple of Wingull had. Wailord appears, and is willing to help bring all of the Pokémon to the other island, riding on its back. Aggron, Lairon, and Aron are all happy to hear that. As the sun sets, Wailord brings the Pokémon to the other island. When the spotlights turn on, Meowth announces the appearance of Azumarill as he is wearing a suit and a hat. Azumarill is lowered to the stage with a crown on her head, with smoke across the stage, and begins singing. Azumarill continues to sing as it walks down the steps and closer to the audience. The Pokémon on stage dance along with Azumarill's singing. Meowth and Wobbuffet beat drums, as everyone enjoys the rest of the festival. Even Ghost-type Pokémon join in, and scare some of the Pokémon.