Did you Know: The last 4 generations of Pokemon games are set in 4 different locations of Japan, as shown in this image
But wait! There's More!
Unova, the 5th Generation region, is set in a whole new Continent, which (im not happy with this next map) is speculated to be America (New York)
This goes Further with the Character of Looker, who makes his first appearance in Sinnoh, speaking to the player clearly (if not a bit odd)
However in his appearance in Unova, he speaks with an Accent, to indicate whilst both games are localised for the player, the core language of each country is different...