Subscribers to the new service will be able to use the network in Japanese while still linking up with the site’s 75 million, mostly English-speaking monthly users. The venture won’t be easy. Unlike the U.K., France and Germany, which MySpace entered earlier this year, Japan already has an established social-networking site–the invite-only Mixi, with 5 million members. MySpace Japan will be open to anyone. But analysts say Mixi’s exclusivity fuels user loyalty. “Users will have to migrate en masse [to MySpace] to make it worthwhile, and Mixi user loyalty is very strong,” says Hiroshi Kamide, an analyst with KBC Securities Japan.

With MySpace’s U.S. growth inevitably slowing, the Asia market beckons. The same source says Murdoch’s MySpace move into China (an even trickier country for a site that promotes user-generated content, given Beijing’s censorship issues) will likely come next year.