Gennai Shiraga is an eccentric old man, and one of Otaru's neighbors. He is a skilled inventor and repeatedly comes up with elaborate gadgets to help Otaru out.
He was first portrayed in English by Doug Stone in Animaze's dub of Saber Marionette J Again. French Tickner then took on the role in Ocean's dub of Saber Marionette J. After that, Paul Boucher initially voiced the part in Blue Water's dub of Saber Marionette J to X, before being replaced by Dave Kelly.