Mixi.jp social networking going public

While I'm on the subject of social networking, Kenji Mori reports that mixi.jp, a major Japanese social networking site (Wikipedia info here) is going public on the Tokyo Stock Exchange in September.  While the potential valuation (over $1B US) seems absurd, at least as a public company we should get some insights into the inner workings of one social networking company - all the others I'm aware of are private of captive of a larger organization.

Fukumimi is already dissecting their prospectus (and reporting in English!).