Dojin-kai

The is a yakuza organization headquartered in Kurume, Fukuoka, on the Kyushu island of Japan, a designated yakuza syndicate, with approximately 310 members. As well as being known as a militant yakuza organization, the Dojin-kai has also been known as a de facto drug cartel, as its activities have allegedly included large-scale drug trafficking, specifically methamphetamine trafficking, which is traditionally shunned in the yakuza world.

With its activities of drug trafficking, the Dojin-kai has allegedly been Japan's largest wholesale dealer in drugs since the late 20th century, after the disbanding of three other yakuza groups based in northern Kyushu; Tagawa-based Sadaoka-gumi, known as Japan's Methlord in the Showa era, which was crushed by the Taishu-kai, Okawa-based Hamada-kai, and Kumamoto-based Yamano-kai.