Pokémon: The First Movie – Mewtwo Strikes Back was theatrically released in Japan on July 18, 1998.
Directed by Kunihiko Yuyama, the film follows Ash, Misty, and Brock as they travel to New Island and encounter Mewtwo, a genetically engineered Pokémon. Its story explores identity, creation, cloning, and the relationship between humans and Pokémon.
The Japanese release came after the television anime had already become a major success. The film was distributed by Toho and was paired with the short film Pikachu’s Summer Vacation in theatrical presentations. It became the first feature-length theatrical film in the Pokémon anime film series.
International release dates are often confused with the Japanese premiere. Warner Bros. released the English-language version in North America on November 10, 1999, more than a year later. The English version also presented a somewhat different treatment of Mewtwo’s origin and themes from the Japanese film.