This is a great chart that I got from Jake Adelsteins website Japan Subculture Research Center.  This graph does a good job of describing the general structure of a Yakuza Gang.  Now not all the clans adhere to this structure, but smaller gangs that make up the larger federation generally follow this model. I also like how they include both the corporate brother and the real estate operator, these are associate which allow the Yakuza to exploit the relevant field.  The Yakuza’s strength comes not only from the every day operations prostitution, extortion, theft, but by infiltrating and rigging stock transactions, and crooked real estate deals.

http://www.japansubculture.com/resources/yakuza-group-structure/