The first Pokémon games launched in Japan on the Game Boy. Pocket Monsters Red and Green were released for Nintendo's monochrome handheld on February 27, 1996.
The Game Boy was especially important because its Link Cable allowed players to connect two systems. Tajiri used that feature as the basis for trading Pokémon between players, turning a technical limitation into the series' defining social mechanic.
The original games were role-playing games developed by Game Freak and published by Nintendo. They used the Game Boy's portability to encourage players to carry their collections and meet others for battles or trades.
Outside Japan, the games were later released as Pokémon Red and Blue. Japan's Green version was not released internationally in its original form, although its content influenced later overseas versions and remakes.