Pokémon: The First Movie was released in Japan in 1998.
Known in Japan as Mewtwo Strikes Back, the film was the first theatrical movie in the Pokémon anime film series. It focuses on Mewtwo, a genetically engineered Pokémon who questions his identity and challenges the humans who created him. The story combines action with themes of cloning, science, and personal identity.
The Japanese theatrical release took place on July 18, 1998. The film was later adapted for international audiences, with the English-language version released in North America in November 1999. That difference in dates is a frequent source of mistaken answers.
The movie also included Pikachu’s Summer Vacation as a companion short in many theatrical presentations. A CGI remake, Pokémon: Mewtwo Strikes Back—Evolution, followed in 2019, but it is a separate film rather than the original movie’s first release.