The position first appeared in around the 11th century when the samurai rank system was created, and it fulfilled the role of serving the household institution of court nobles, however, it ranked under Shodaibu (aristocracy lower than Kugyo) who would raise to Shii (Fourth Rank) or Goi (Fifth Rank), mainly placed at Rokui (Sixth Rank) (rarely, some rose to Goi).
11世紀の侍階層出現の頃より現れて公家の家政機関に奉仕する役目を担うが、四位・五位へ昇進する諸大夫より下位に置かれて、基本的には六位に置かれていた（稀に五位に昇る者が存在した）。