What were the first Pokémon games called in Japan?

The first Pokémon games in Japan were called Pocket Monsters Red and Green.

Game Freak developed the pair for Nintendo’s Game Boy, and Nintendo released them in Japan on February 27, 1996. The games used different version-exclusive Pokémon, encouraging players to trade through the Game Boy Link Cable.

International releases used the names Pokémon Red and Blue rather than Red and Green. Japan later received a revised Blue version, and material from that version helped form the international Red and Blue releases. This is why many players outside Japan know the debut pair as Red and Blue.

The original games introduced the first generation of Pokémon, the Kanto adventure, Gym battles, the Pokémon League, and the Pokédex. Their version structure became a defining feature of the main series for later generations.