What is the English title of the Japanese game Pokémon Green?

The Japanese game Pokémon Green was paired internationally with Pokémon Blue.

Pocket Monsters Red and Green were the first Pokémon games, released in Japan in 1996. Nintendo later released an enhanced Blue version in Japan, and that Blue-based version was reworked for international markets as Pokémon Red Version and Blue Version.

This history creates a frequent misunderstanding: the Japanese Green version was not simply renamed Blue in every market. Instead, the overseas releases used Red and Blue, while the original Green remained a Japan-only first-generation title for many years.

Pokémon Yellow followed as an enhanced edition featuring Pikachu more prominently and reflecting elements of the anime. Crystal later served a similar enhanced-version role for Pokémon Gold and Silver, so it should not be confused with the first generation's Blue version.