Kenji Kasahara

Age: 32
Companies: Find Job, Mixi

Internet pioneer Kenji Kasahara started Find Job, a recruitment Web site, more than a decade ago while still a junior in college. Within a few years, he was already making millions of dollars annually. After learning of the popularity of social networking sites in the U.S., Kasahara set up invitation-only social network Mixi in 2004. Now, Mixi is Japan's most popular social networking site with 15 million users and 1 million minicommunities created and policed by users. Although competition from networking titans Facebook and MySpace (NWS) has slowed its growth, Mixi has started to build a Chinese-language version. Mixi went public in September 2007 and was among last year's most highly anticipated IPOs.