Yoro Ginsei is a minor antagonist in Sword of the Samurai.
Ginsei was the guard captain of Lord Toda, who plotted against the Shogun. Following the death of his master, Ginsei became a Ronin with a hatred for samurai, while the rest of Toda's retainers committed sepukku rather than suffer dishonor. Ginsei continued to live in a solitary hut near a village of Rokuro-Kubi, a few days' travel south of the Mizokumo Fens. It is known that he had a wife and two children while in the service of Toda; what happened to his family after he became an outcast is unknown.
A young samurai travelling to the Shios'ii Mountains to challenge Ikiru, who had stolen the magic sword Singing Death from the Shogun Kihei Hasekawa, chanced upon Ginsei's hovel and was challenged by the ronin to a fight to the death. Unable to refuse without soiling his and the Shogun's honor, the young samurai engaged him and killed him after a hard struggle.
As a former samurai, Ginsei was a master in the use of the katana. Although he did not have any skills immediately useful in face-to-face combat, he was trained in deflecting arrows and missile weapons used against him.