The Okubo-gumi was a Japanese yakuza family which was based in Hiroshima Prefecture. It was founded by Kenichi Okubo, who became a respected elder statesman of the yakuza and a "boss of bosses" of sorts. In 1949, Okubo engineered a war between the Doi-gumi and the Yamamori-gumi with the objective of seeing to the destruction of Kiyoshi Doi's organization; Doi was an avowed enemy of Okubo's distant relative Toru Ueda.