The is the third largest of Japan's yakuza groups, with approximately 1,600 members. It is based in the Kantà  region, and was one of the first yakuza organizations to begin operating overseas.
The Inagawa-kai was founded in Atami, Shizuoka in 1949 as the by Kakuji Inagawa. Most of its members were drawn from the bakuto (traditional gamblers), and illegal gambling has long been the clan's main source of income. It has also expanded into such fields as drug trafficking, blackmail, extortion, and prostitution.
The Inagawa-gumi was renamed the Inagawa-kai in 1972. After Kakuji Inagawa, the gang was led by Susumu Ishii, who led it to unprecedented financial prosperity during the 1980s Japanese bubble economy. At one point the clan's assets were estimated to be over $1.5 billion. After Ishii's death in 1990, Inagawa's son Toi Inagawa took over as kumicho and led the clan until his death in May 2005. Yoshio Tsunoda took up the mantle in 2006, heading the clan until his death in February 2010.
The Inagawa-kai quietly helped to provide relief in the wake of the 2011 TÃ Âhoku earthquake and tsunami by sending supplies to affected areas. As a whole, the group shipped over 100 tons of supplies, including instant ramen, bean sprouts, paper diapers, batteries, flashlights, tea and drinking water, to the TÃ Âhoku region.
Inagawa-kai's renowned figures in the 20th century include Tatsuo Deguchi (known as the "Moroccan Tatsu" or "Tatsu of Morocco"), Kingo Yoshimizu, Kijin Inoue, Takamasa Ishii, Haruki Sho, and Kiichiro Hayashi.
In April 2025, Jirà  Kiyota, the former fifth kaichà  (ä¼Âé·, chairman) and then-current sà Âsai (ç·Âè£Â, supreme advisor), died of illness. As a result, Kazuya Uchibori became the leader of the Inagawa-kai in both name and reality as its sixth kaichà Â.