I'm with KylieDog. The genres diverge based on gameplay, not country of origin.
http://en.wikipedia.org/wiki/Console_rpg#History_and_classification
After the success of role-playing video games such as Dragon Quest and Final Fantasy, the role-playing genre eventually diverged into two styles, Japanese role-playing games and Western role-playing games, due to cultural differences, though roughly mirroring the platform divide between consoles and computers, respectively. Finally, while the first RPGs offered strictly a single player experience, the popularity of multiplayer modes rose sharply during the early to mid-1990s with action role-playing games such as Secret of Mana and Diablo. With the advent of the Internet, multiplayer games have grown to become massively multiplayer online role-playing games, including Lineage, Final Fantasy XI, and World of Warcraft.
After the success of console role-playing games in Japan, the role-playing genre eventually began being classified into two fairly distinct styles: computer RPG and console RPG, due to stylistic, gameplay and/or cultural reasons; with the latter having become popularized and heavily influenced by early Japanese video games such as Dragon Quest and Final Fantasy. In the early 2000s, however, as the platform differences began to blur, computer RPGs and console RPGs were eventually classified as Western role-playing games(or WRPGs) and Japanese role-playing games (or JRPGs), respectively.
