In the movie, Pikachu and his friends are excited to attend the Melody Tree Festival, where Meloetta is scheduled to perform her special song. The festival takes place in a beautiful forest, where the Melody Berries grow and are an important part of the festival's celebrations.
As Meloetta starts her performance, the calm atmosphere is suddenly disrupted by a powerful Sandstorm attack. The tree holding the Melody Berries is destroyed, and the berries are scattered all around the forest. Everyone is shocked and saddened by the sudden turn of events.
Pikachu and his friends are determined to help Meloetta and retrieve the lost Melody Berries. They split into teams and embark on a quest throughout the forest to locate the scattered berries. Along the way, they encounter various challenges and obstacles, including battling other Pokémon, navigating through dangerous terrain, and dealing with unfriendly humans.
As they collect the berries, Pikachu and his friends learn about the history and significance of the Melody Tree Festival, as well as the importance of preserving the natural environment. They also bond with Meloetta, who is grateful for their help and support.
After retrieving all the Melody Berries, Meloetta performs her special song at the festival's conclusion. Pikachu and his friends dance and sing along, happy to have been a part of such a memorable event. In the end, they return home, having learned valuable lessons about teamwork, friendship, and nature.