What were the original Japanese game titles later localized as Pokémon Red and Blue?

The original Japanese games were titled Pocket Monsters Red and Green; they were later localized internationally as Pokémon Red and Blue.

Japan received Pocket Monsters Red and Green on February 27, 1996. A revised Japanese Blue version followed later, and its updated artwork and text formed the basis for the international Red and Blue releases.

This is why the first Pokémon generation has different version names depending on the market. Japan’s original pair used Green, while North America, Europe, and other regions generally received Red and Blue. The Japanese Green version was not released internationally in its original form.

The distinction is not merely cosmetic: version-exclusive Pokémon encouraged trading between players. Pokémon Yellow later served as an enhanced release inspired partly by the television anime and its portrayal of Pikachu.