Viacom (NYSE: VIA) is relaunching its Japanese mobile music portal as a social networking service from September this year, changing its name from Flux to myMTV. The site, which had been around since June 2005 under its original name, will be ad-supported, free and available with all the major mobile operators. The idea is to continue to offer clips of MTV programs, music videos and catalog of “mastertones,” and to add new services such as personalized pages, playlists and video sharing. Wireless Watch Japan calls the idea of adding social networking to MTV’s mobile site an “obvious” evolution: not only has Flux in Japan already been offering social networking over its broadband service; but social media via mobiles has been seeing explosive growth in the country.

Flux in Japan differs from what MTV does with Flux elsewhere, namely the UK, where Flux first started. There, it has always had a mobile/social media element, encouraging viewers to use their mobile phones to upload content onto the Flux site; in turn, that material was incorporated into programs for the MTV Flux television channel. What is different with myMTV is that the content will stay on mobile, rather than make its way eventually to TV—which may indeed be used as an incentive to get people to use it in the West, where the mobile internet is far less popular than it is in Japan.

MTV says that myMTV may well be rolled out markets beyond Japan. Back in February at 3GSM, Greg Clayman, SVP for mobile media at MTV, claimed MTV Mobile was generating one million streams per month globally. In addition to Flux, MTV has a number of niche mobile sites dedicated to separate areas like music videos and comedy clips.