Pokémon Red Version is the international version of Pocket Monsters Akai. Compared to the earlier version, Red has updated graphics and audio, some changes to area layouts, and significantly overhauled code, all of which in fact originate from the Japanese release of Pocket Monsters Ao.
Red and Akai share the same version-exclusive Pokémon; in order to complete the Pokédex, players must trade with owners of Blue version.