According to the "Kanshoku konan" ("官職今案") by Tomokiyo TAKADA, during the period of the Northern and Southern Courts (Japan), as with Dainagon, there were only temporary personnel and official personnel were nonexistent.
南北朝時代(日本)以降は大納言と同じく権官ばかりで正員がなくなったことが高田与清（たかだともきよ）『官職今案』に見えている。