Little is known about the background of this Shiro, and there is a mismatch between the imina (personal name) of Kiyonobu claimed by the manuscript passed down generations, Motonaka claimed by the recent genealogy, and the theory that stated him to be Kyuji.
この四郎については詳しい来歴は知れず、諱も清信とする後代の伝書、元仲とする近世の系図、久次とする説など一致を見ない。