Yamaguchigumi

Yamaguchi-gumi is the largest yakuza syndicate in Japan and, by some accounts, the world. It originated in Kobe, Hyōgo Prefecture, and was founded in 1915 by Harukichi Yamaguchi as a small neighborhood group that grew into a nationwide criminal organization. The name combines the founder’s surname with gumi, meaning group. The organization operates through a network of interlinked families and subgroups, with its headquarters in Kobe and outward reach across Japan and into overseas territories.

Organizationally, the Yamaguchi-gumi is structured as a hierarchical crime family. The supreme leader is the kumicho (boss), supported by senior advisers, underbosses, and numerous divisions or groups run by chiefs. The group engages in a range of illegal activities, including extortion, loan sharking, illegal gambling, drug and arms trafficking, money laundering, and the control of legitimate businesses such as construction and real estate to generate revenue and influence.

Public authorities designate the Yamaguchi-gumi as a boryokudan, or dangerous organized crime group, and have pursued extensive anti-crime measures, contributing to declines in membership and tighter corporate and financial controls. Estimates of membership vary, with several thousand members reported in recent years, though exact figures are difficult to verify and have fluctuated with law enforcement pressure.

One notable episode in its recent history was a major internal split in 2015, when a prominent faction separated from the main organization, leading to violence and a reorganization that continued for years. The group remains a focal point of Japan's efforts to suppress organized crime, alongside broader international law-enforcement cooperation on related activities.