Hiroshi Yamamoto
The situation that led to the war is when Hiroshi Yamamoto broke from the Yamaguchi-gumi along with 18 lieutenants and 3,000 other members to form his own organization, the Ichiwa-kai. The split stemmed from professional jealousy: Yamamoto had been seen as a contender for the role of "kumicho", or supreme godfather, in the Yamaguchi-gumi, and was unhappy when a rival, Masahisa Takenaka, was elected to the position by other members, and most importantly by Fumiko Taoka, widow of Kazuo Taoka.