What are the Japanese first-generation Pokémon games collectively known as?

The Japanese first-generation Pokémon games are collectively known as Pocket Monsters Red and Green.

They launched for the Game Boy on February 27, 1996, and introduced the original creature-collecting system, including battling, evolution, trading, and a regional Pokédex. Their Japanese branding differs from the titles used in most international markets.

Outside Japan, the pair became Pokémon Red and Blue. The original Japanese Green version was not released internationally as Green; instead, the overseas games used the Japanese Blue version as a technical and visual foundation while retaining a distribution of Pokémon comparable to the original Red and Green pair.

This naming difference is a frequent anniversary mix-up. Pokémon Blue did exist in Japan, but its initial release was a later special version before it reached general retail. Pokémon Yellow was an enhanced release inspired partly by the anime and was not one of the original Japanese launch pair.