Nothing has been made clear, except for the fact that it came from Zaichokanjin (the local officials in Heian and Kamakura periods) who had been appointed to Suo no Gon no suke (supernumerary vice governor of Suo Province) by heredity for generations in Suo Province.
代々周防国で周防権介を世襲した在庁官人の出であること以外は不明である。