Ghetz was probably a wrestler that practiced on mainland Zenan around the time Greco wrestled. In an unknown incident, Ghetz gave his life to save Greco, teaching him an important lesson at the same time. This changed Greco; he became a spiritualist and moved to El Nido, and took care of Ghetz's sister Romana. Ghetz's spirit later appeared to Greco to teach him his ultimate technique, GraveDigger.
Greco's Japanese name is Gilbert, Ghetz's is Getz, and Romana's is Astrud. This is a reference to musician Stan Getz and Brazilian guitarist João Gilberto, who released an album called Getz/Gilbert in 1964. Astrud is the name of Gilberto's wife, who became famous after the album's release.