Initially, the post was held by one official, and later one Kenkan (powerful official) was added, and their rank was equivalent to Jushichiinojo (Junior Seventh Rank, Upper Grade); however, in later times it became customary to give the post a Goi (Fifth Rank) or higher ranking.
定員1名（後に権官1名追加）・従七位上相当（ただし、後世では五位以上が慣例となる）。