Nintendo's Pokemon franchise can be considered an enduring worldwide phenomenon, but nowhere is that more true than in its native Japan. Case in point, Famitsu publisher Enterbrain reports that the latest installments in the dual-release franchise, Pokemon Black and Pokemon White, have combined to set a new first-week sales record for the franchise upon their release in Japan on September 18.

　　Once a noble breed, Pokemon have been hunted to near extinction. As relayed by gaming blog Andria Sang, Pokemon Black and White logged opening-week sales of 2,637,285 units, according to Enterbrain's initial estimates. That figure easily bested 2006's Pokemon Diamond and Pearl, which sold 1,586,360 units during their first week at retail.

　　Pokemon Black and White introduce a handful of changes to the established gotta-catch-'em-all formula. Developer Game Freak has expanded the game's online functionality through features such as Global Link, where players can access special content by uploading their save files to a Web site. Black and White also introduce more than 150 new Pokemon that players can add to their Pokedexes.

　　As for the dual name, Nintendo traditionally releases near-identical editions of the same Pokemon game under slightly different monikers, encouraging players to exchange captured monsters between versions.

　　For more on Pokemon Black and White, check out GameSpot's previous coverage.