Johto is the main region introduced in Pokémon Gold and Silver, the Generation II games released for Game Boy Color.
Johto lies west of Kanto, and the games allow players to revisit Kanto after completing Johto's Pokémon League challenge. Towns such as New Bark Town, Violet City, Goldenrod City, and Ecruteak City give the region a distinct cultural and architectural identity inspired by Japan's Kansai area.
Generation II added 100 new Pokémon, bringing the total species count to 251. Gold and Silver also introduced breeding, held items, a day-and-night cycle, and Pokémon with different genders, making Johto a major expansion of the original formula.
Because Kanto and Johto share one connected game world, players sometimes mistake Kanto for the Generation II setting. Kanto is still playable in the sequels, but Johto is the region where the new adventure begins.