When did the first season of the Pokémon animated series premiere in Japan?

The first season of the Pokémon animated series premiered in Japan on April 1, 1997.

Known in Japan as Pocket Monsters, the series follows Ash Ketchum and his partner Pikachu as they travel through the Pokémon world. The first season is commonly called Pokémon: Indigo League in English-language markets, although the Japanese broadcast originally used the simpler title Pocket Monsters.

The season aired on TV Tokyo and introduced viewers to characters such as Misty, Brock, Professor Oak, and Team Rocket's Jessie, James, and Meowth. Its story was based primarily on the first-generation games and their Kanto setting.

The Japanese premiere predates the English-language U.S. launch, which began in September 1998. Those different dates sometimes cause confusion when fans discuss the anime's beginning. The April 1 date refers specifically to the original Japanese broadcast.