The Hiroto-gumi was a Japanese yakuza syndicate that was based on the west side of Tokyo during the 1960s. Led by Yamanosuke Hiroto, the black-clad gang was originally allied with eastern Tokyo's Mojo-gumi until, in 1969, Kenji Mojo attacked Hiroto's honor by insulting his wife. The Soviet KGB, which attempted to control Tokyo's underworld, was forced to wipe out both yakuza factions' leadership to prevent their gang war from getting out of control, and they assumed direct control of both factions.