Up to two to three personnel could be appointed to this post, and they were selected from among the Tenjobito (a high-ranking courtier allowed into the Imperial Palace) of the Fifth Rank, with particular favor for individuals from families of nobility and who were scholarly gifted.
定員は2~3名で、五位の殿上人の中から、家柄がよく学識才能のある者が特に選ばれた。