Scientists genetically create a new Pokémon, Mewtwo, but the results are horrific and disastrous.
When a group of scientists are offered funding into genetic research if they agree to try and clone the greatest ever Pokémon, Mew, the end result is success and Mewtwo is born. However Mewtwo is bitter about his purpose in life and kills his masters. In order to become the greatest he throws open a challenge to the world to battle him and his Pokémon. Ash and his friends are one of the few groups of trainers who pass the first test and prepare for battle. However they soon find out about further cloning and Mewtwo's ultimate plan for the earth.
A scientist has found a way to genetically clone one of the Pokemon named Mew. His invention is named Mewtwo. Mewtwo then clones other Pokemons on his own. Sort of a revolt of the Poki. Each Pokemon has a different kind of power. The hero, Ash Ketcham ventures with his friends to the villain's island, where battles take place between lots of different kinds of and their clones.
- Pokémon: The First Movie (Pocket Monsters the Movie: Mewtwo's Counterattack) is the first Pokémon anime film directed by Kunihiko Yuyama, the chief director of the Pokémon television series. It is the first theatrical release in the Pokémon franchise.
It was released in Japan on July 18, 1998. The English-language adaptation, produced by 4Kids Entertainment and distributed by Warner Bros. Pictures (under its Kids' WB banner), was released in North America on November 12, 1999.
The film primarily consists of three segments: Pikachu's Vacation, a 21-minute feature focusing on the series mascot Pikachu; Origin of Mewtwo, a 10-minute featurette that functions as a prologue to the main feature; and Mewtwo Strikes Back, the main 75 minute film feature. The North American version omitted Origin of Mewtwo from the package before its U.S. theatrical run due to its dark nature, as the target MPAA rating was G; the first two minutes were restored in the film's release on VHS and DVD as The Story of Mewtwo's Origin. The featurette was eventually dubbed and restored as a special feature in the U.S. release of the direct-to-video follow-up film sequel Pokémon: Mewtwo Returns as The Uncut Story of Mewtwo's Origin.
As Pokémon was extremely popular when the film was released, it was a box office success worldwide. The First Movie topped the box office charts in its opening weekend, and eventually grossed US$163.6 million worldwide, despite negative reviews from film critics.