Ash meets five residents who come together to save the day when a series of threats endanger the annual Wind Festival and the entire population of their home, Fula City
Every year the citizens of Fura City celebrate a Wind Festival. Where people live together with the wind. Long Ago, on the final day of the festival the Legendary Pokemon Lugia and bestow the blessings of the wind upon the people. This Film Focuses on Everyone's Story. from Lisa, a high school girl who is just starting out as a Pokemon trainer, to Karachi, a guy who can't stop lying to Torito, a researcher who lacks confidence in himself, to Hisui, an old lady who hates touching Pokemon, and Rarugo, a mysterious young girl who watches over the forest by herself.
- Fula City was founded on barren land that was suddenly engulfed in flames due to the mysterious Pokémon Zeraora. When the Pokémon and people began helping one another, Lugia, moved by the cooperative nature of them, cleared the fire. Since then, the city has held a wind festival every year to celebrate Lugia's help while Zeraora disappeared supposedly cursing the mountain and surrounding area near the city.
High school student and former track runner, Risa, is asked by her younger brother, Rick, to attend the festival to capture a wild Eevee for him as he is in the hospital from a broken leg. She agrees, albeit reluctantly, but has no prior training and does not know how and where to capture one. Ash Ketchum and his Pikachu arrive in Fura City in time to rescue Margo, the daughter of Mayor Oliver, from a group of lemonade bullies and decides to enter the Pokémon catching contest held at the festival. Toren, a timid and self-deprecating scientist who owns a Chansey, has to give a speech at the lab about his progress on Pokémon, but is too nervous to talk. Callahan attends the festival with his sister Mia and her daughter Kelly. Kelly suffers from low immunity, so Callahan invents tall tales about him being the best trainer when he does not even have a Pokémon. Harriet is an anti-social old woman who dislikes being around Pokémon, but while at the lab to give Toren a paper for him to sign, accidentally gets love scent on her resulting in Pokémon following her wherever she goes.
Margo heads into the woods to play with a Teddiursa and Ditto and to care for the Zeraora who has been hiding in a ruined building hidden deep. Mistaking Callahan's loud proclamations, Risa asks for advice on where to find an Eevee with him telling her that it is extremely rare and can be found in the mountains. She later comically finds out that he was lying. Toren meets with Callahan and convinces him to give his speech and in return will help him win the Pokémon catching contest. During the contest, Callahan takes pity on a Sudowudo who had upset a Golduck and rescues him with the former Pokémon now following him. Ash and Pikachu meanwhile heroically stop a rampaging Tyranitar that got a cord stuck around his neck. Ash comes in second with an honorary award from Oliver while Callahan comes in first boasting about a rare Pokémon in the woods intriguing everyone, but worrying Margo.
The next day, Risa comes to Ash to help her capture an Eevee, which they successfully manage to do, and bond. Harriet, upset over the amount of Pokémon that have been following her goes to Toren to ask for an antidote, but says it will take time resulting in her staying with him. The festival is halted due to someone sabotaging much of the city's transportation and electrical workings. Ash, Risa, Margo, Callahan, Kelly, Mia and their Pokémon help clean the mess up, but Callahan is nervous as he has to make it to Toren's speech. While they manage to clean it up, Callahan rushes to the presentation with everyone following him. Toren tries to give the presentation on his own, but accidentally plays footage of him helping Callahan at the contest in time for everyone to see it. Upset over her uncle's lies, Kelly passes out from exhaustion. Harriet catches Team Rocket (who have been posing as Lum Berry juice salesmen) who make off with a bottle of Effect Spore. However, the trio accidentally lose it in the woods where it slightly cracks.
Harriet awakens the next morning to discover that the windmills that line the city have stopped turning as the winds have ceased while the eternal flame (a light held on the highest tower in the city to contact Lugia) has mysteriously disappeared. The whole town is in an uproar, but Ash, Risa, Toren, Harriet and Oliver manage to locate clues on what has happened to the flame. Margo tries to protect Zeraora from two poachers, but are rescued by Ash and his friends just in time. Margo reveals that she took the flame to stop the festival so that she can hide Zeraora. Oliver then reveals to her that the fire was started by humans who were trying to find Zeraora who was just protecting the Pokémon. The mayor before Oliver held this secret and since then he has kept it too. Suddenly, the Effect Spore bottle cracks engulfing much of the forest and the city and the group decide to work together to stop it.
Callahan discovers that Mia and Kelly are trapped in a gondola while the city is being engulfed and Sudowoodo allows itself to be captured by him so that they can save the city. Toren gets to the lab and finally stands up for himself so that he can get to work on an antidote. Harriet, Callahan and Oliver meet at the mayor's house to chart a plan with Harriet revealing that she helped build the giant disused windmill up in the mountains and she and Callahan head there. Ash, Risa and Margo try healing Zeraora so that he can help. A fire suddenly breaks out in the forest, killing the electricity and destroying much of the lab equipment, but Team Rocket arrive with their Lum Berry juice cart and Toren begins creating a concentrated antidote with it. While heading up the mountain, Harriet reveals that she had burned her hand while trying to rescue her Snubbull from the burning windmill when she was younger, resulting in her becoming distant from Pokémon. It managed to rescue the key needed to start it and she and her numerous Pokémon help clear a path.
Zeraora awakens and begins rescuing Pokémon. While Ash and Margo decide to go follow it, the former tasks Risa with taking the eternal flame back to the tower. She worries about her foot injury, but her Eevee gives her the confidence to run. She removes her shoes and runs barefoot to the tower where she gets unexpected help from Rick, who is using a satellite to track her. Ash and Pikachu end up fighting Zeraora, who still distrusts humans, but Margo manages to get through to it and they try helping to put out the flames. Toren arrives at the windmill to give the antidote to Callahan who tosses it into the turbines while Harriet and the Pokémon turn the blades. Risa gets the eternal flame to the top, and Lugia arrives to put out the fire. Everyone resumes the festival where Oliver gives a speech based on something Ash had said about working together with the help of "Pokémon Power". Ash, Risa, Callahan, Kelly, Mia, Toren, Harriet and Margo all join the festivities changed by their experiences.
During the credits, stills reveal the characters after their adventure. In a post-credits scene, Rick is revealed to be the ecstatic blogger who appeared throughout the film. Risa barges into his hospital room and angrily demands an explanation for him knowing where she was (it is implied that the sunglasses he had given her at the beginning were tracking her). Ash and Pikachu are seen walking down the road wondering what their next adventure will be.