It exists two types of yakuza, clan- yakuza and freelance yakuza.
Freelance yakuza
Freelancing yakuza is a yakuza that not commit any bigger crimes and belongs to a little group of hustlers.
They have however some difficulties to survive or not come into jail, because the clan- yakuza not allows anyone other to operate within their territories. Clan- yakuza can tip the police about crimes that the freelance yakuza haven´t commit.
If the freelance- yakuza earns to much money, the clan- yakuza kills the freelancing- yakuza or make him disappear without a trace.
Klan- yakuza can however have a certain use of a freelance yakuza. If the clan- yakuza shall do something that they not want the clan to be associate with, they can turn to a freelancing yakuza that, for a sum of money, does the job for them.
A freelance- yakuza can also be used as a scapegoat if it acquires a guilty to a crime.
If a freelancer is a truly genius he can manage to begin his own clan. Usual a freelance- yakuza becomes, if they not gets killed,a member in a clan.
Yakuza Klan
The clan have been compared to the Sicilian mafias "family". The clan is structured much like a common family in traditional Japan. The clan has a hierarchy structure. The clans head chief is called Oyabun, that means Father. Beneath him he has his children(Wakashu) and brothers(Kyodai). These are not his real children and brothers, only designations of rank and position they have within the clan. All the members in the clan obey the Oyabun and in return he protects them against all dangers.
Oyabun is almighty within the clan and his words is the law. All obey him without hesitation or concern for their own life. Beneath him, oyabun has an adviser that is called Saiko-komon and he has a staff of advocates, accountants, secretaries and advisers. The children's (Wakashu) boss called Waka gashira. He is number two in the clan after Oyabun, not in rank but in authority. He acts as a middleman to see that the oyabun's orders are being accomplished.
The children leaders over their own (sub) gangs and over time can move up in the structure. In that way the clan becomes a ramification with several sub families. The oyabun's "brothers" or Kyodai, boss is called Shatei gashira. Shatei gashira is of higher rank than Waka gashira but doesn't have more authority. "The Brothers" have their own "children" or "younger brothers"(Shatei). Shatei, has its own sub gangs etc. Everyone obeys its gangleader, but it's always the oyabun's word that counts.