Yakuza (ヤクザ?, [jaꜜkuza]), also known as gokudō (極道?), are members of transnational organized crime syndicates in Japan. The Japanese police, and media by request of the police, call them bōryokudan (暴力団?, "violence group"), while the yakuza call themselves "ninkyō dantai" (任侠団体 or 仁侠団体?, "chivalrous organizations"). The yakuza are notorious for their strict codes of conduct and very organized nature. They have a large presence in the Japanese media and operate internationally with an estimated 103,000 members.
It used to be that only yakuza had tattoos (as the practice was thought “unclean”). Made it hard for them to go legit as well. (and would cause quite a discussion when my Japanese business cohorts would see us with tats.)