Enjoyed reading "Tokyo Vice", a non-fiction by American joournalist/writer Jake Adelstein.
The author was a crimereporter for the Yomiuri Shinbun (not the English-language Daily Yomiuri), which is unusual for a gaijin. In his book, Mr Adelstein described his personal encounters with Japanese cops, gangsters, hostesses, etc.. to get his scoops. The book is an eye opener of how entrenched the yakuza is within the Japanese society. Yakuza likes to use the word gokudo (極道), meaning "the ultimate path", to refer to their lifestyle. To many Japanese, they are like the modern-day samurai, the harbingers of traditional Japanese values such as honor and brotherhood. Sort of like the Last of the Mohicans (for some reason the author likes to use the boyscout analogy). In Japan, one can go to any convenient stores or bookstores to find Yakuza cartoons and fan magazines. Within the past decade, yakuza organizations have become experts at real-estate and stockmarket investing, and the size of the yakuza-controlled underground economy is estimated to be at 20 trillion yen. While interviewing his sources, the author interacted with human trafficking victims from Eastern Europe who are lured into Japan by hostess clubs with links to the underworld. His reporting played a significantly role in raising international awareness about towards human trafficking in Japan, which eventually led to the Japanese government adopting stricter regulations against human trafficking. A very provocative book, with a lot of sex and violence, but with lots of humor. For more information, visit the author's blog: http://www.japansubculture.com/