The Yakuza are believed to be one of the largest organized crime phenomena in the world and have been around longer than the Sicilian mafia. Their origins can be followed far back as to the year 1612 when men known as kabuki-mono (the crazy ones), came to the attention of local authorities. Their odd clothing, style, distinctive haircuts and anti-social behavior gained the attention of mainstream society. They have gained notoriety not just in Japan but around the world for their activities.
In Japanese legal terminology, Yakuza organizations are referred to as bôryokudan, literally violence groups. Yakuza members consider this an insult, as bôryokudan is a term which can be applied to any violent criminal. It is generally believed that most Yakuza members come from poor backgrounds or are on the margins of society.They mainly make their livings from unlawful activities, such as gambling, drugs, prostitution and extortion. For many poor people the Yakuza have become like a family that protects them. After the earthquake in Kobe the Yakuza arranged financial aid and even a helicopter for local people most effected by it. Many local business see the extortion money as a form of 'tax' and the police are sometimes reluctant to become involved.
For the Yakuza it doesn´t matter which country you come from or from which class of society you belong to, it is not too hard to become a member of the 'New Yakuza'. The Yakuza still see their role as that of taking care of those on the margins of society. The Yakuza is an all men's society. They don't generally trust women and view them as being weak. They believe that women cannot fight like men, that women are not born to fight. To a Yakuza member, the most important thing is courage. They are prepared to fight to the death, rather than lose the battle. Yakuza members must be willing to die for their boss.
It's common within Yakuza circles to tattoo themselves. Their tattoos can depict their clan's crest. Some Yakuza members tattooed a black ring around the arm for each crime they committed. Tattoos were a mark of strength (some tattoos can take over 100 hours to do) and were also a sign that they were unwilling to accommodate themselves to societies rules and norms. Although tattoos have become mainstream in Japan as well as around the world it is not uncommon for public onsen (Japanese baths) and some capsule hotels not to admit people with tattoos as was my experience in Japan. Many of the older generation still associate tattoos with the criminal classes which may be the reason you don't see to many people showing them off in public places.