Idea of Yakuza organization is that the clan collect membership fee from their subordinates, which could be as high as a million yen (about $10000 USD) per month for member of direct member of the prominent clan. read more
Movies like Battles Without Honor and Humanity and Dead or Alive portray some of the members as violent criminals, with the focus being on the violence, while other movies focus more on the "business" side of the Yakuza. read more