Tadashi Yanai, one of the richest men in Japan, told the Wall Street Journal last week that he was "disgusted" by the video of a couple having sex in a Beijing outlet of the clothing chain Uniqlo. The video quickly went viral in China, and Internet commenters wondered if it wasn't part of some weird publicity stunt on behalf of Yanai's company, Fast Retailing, which owns Uniqlo.

Yanai vehemently denied the suggestion, but it's difficult to think the newsworthiness of the story hasn't helped his company. It certainly hasn't hurt it. Uniqlo already operates 370 stores in China and plans to open several thousand more.

That's a lot of retail, and while many global companies would kill for that kind of exposure in China, Fast Retailing's success on the mainland should be balanced against its possible decline at home. After decades of invincibility, the Uniqlo brand may be on the wane in Japan.