Wikipedia must be skipping over some important details, but it describes him as a two-time college dropout, a nightclub manager in Japan, (EDIT: nevermind, mystery solved! His MIT bio says he was the founder of Japan's Digital Garage and CEO of its first ISP [1]), then he's the president of MIT Media Lab, visiting Harvard Law School professor, on several boards of directors, and runs a VC fund.
I'm not implying he got his money by nefarious means, just that it's interesting to see people who find success (and in this case, downfall) within these institutions despite their unconventional backgrounds.