The first Pokémon animated film was theatrically released in Japan in 1998. Its Japanese release date was July 18, 1998, and its story centered on the genetically engineered Pokémon Mewtwo.
Outside Japan, the film became known as Pokémon: The First Movie, with the subtitle Mewtwo Strikes Back. The English-language version reached North America in November 1999, so the Japanese and North American dates are easy to mix up.
The film expands ideas introduced in the television series, including Pokémon cloning, identity, and the consequences of treating living creatures as tools. It also includes the short film Pikachu’s Vacation in many theatrical versions.
A full computer-animated remake, Pokémon: Mewtwo Strikes Back—Evolution, was released in 2019. That remake should not be confused with the original 1998 film, which was traditionally animated and directed by Kunihiko Yuyama.