Hanzo Shiranui (不知火 半蔵, Shiranui Hanzō) is a background character in the Fatal Fury series and is Mai Shiranui's grandfather. A master of Koppoken and Shiranui-ryuu Ninjutsu, Hanzo was a strict teacher who trained both Mai and Andy Bogard. Hanzo was acquaintances with fellow martial arts masters Jubei Yamada and Tung Fu Rue. Sometime before Fatal Fury, Hanzo and Jeff Bogard faced Wolfgang Krauser simultaneously; Hanzo left the second half of the x-shaped scar on Krauser's forehead.
Hanzo passes away by the time Fatal Fury 3 takes place, leaving the Shiranui clan's legacy to Mai and his martial arts successor to Andy.