Yamaguchi is a guy who works at bar in the slum Trench Town in Violence Jack Harlem Bomber. He recognizes Violence Jack and tells Sabu to tell Slum King that Jack is at his place but saburefuses since his grampa said that Jack fights for weak people like him. Yamaguchi tells him that they'll get wacked if they don't tell them that Jack was with them and he goes off to tell them off screen. When Rose and friends get there, Jack is gone and She whips Yamaguchi and leaves as Sabu hides behind a wall but in a doorway. When trench town is under attack by Laser he realizes that its Jack's presence that makes everyone go nuts. And then...he died... from getting shot up by a machine gun.