In a world where Pokémon and humans coexist, Ash and his friends embark on an adventure that will change the way they see these adorable creatures. After receiving a mysterious invitation to attend a scientific experiment on a secret island, the group encounters Mewtwo, a powerful and enigmatic Pokémon created from Mew's DNA. Mewtwo has been designed to be the strongest Pokémon in the world, but he has also been the victim of a cruel experiment that has left him with deep insecurities about his existence and purpose.
However, in his quest for answers, Mewtwo develops a resentment towards humans, whom he blames for his suffering. Determined to prove his superiority, Mewtwo captures several Pokémon and challenges Ash and his friends to an epic battle. As the conflict unfolds, Ash realizes that beneath Mewtwo's rage lies a profound pain and a struggle to understand his own identity in a world where everyone seems to treat him as nothing more than an experiment.
In the end, the movie addresses deep themes of creation, identity, and what it means to be a living being with emotions. Ash and his friends must find a way to stop Mewtwo, not only to protect their Pokémon but also to help a being that is simply seeking to find his place in the world.