Yakuza call themselves ninkyō dantai (chivalrous organizations) which the Japanese media and police call them bōryokudan (violence group). They are the world's largest criminal organization and have about 103,000 members.[2][3] The three biggest Yakuza families are Yamaguchi-gumi, Sumiyoshi-kai, and Inagawa-kai. During the 2011 Tōhoku earthquake and tsunami, they opened their offices to help refugees and sent dozens of trucks with supplies to affected areas.[4]
