When the kurodo dokoro was founded after the Kusuko Incident in 810, the shikiji at the kurodo dokoro gradually assumed the role of conveying the imperial edict to the Daijokan -- the order had conventionally been conveyed by naishishi (also referred to as naishi no tsukasa; messengers from the palace attendants) at kokyu (the women's quarters of the Imperial Palace).
弘仁元年（810年）の薬子の変をきっかけに蔵人所が設置されると、従来は後宮の内侍司を通して伝えられていた天皇の勅旨の太政官への伝達が、次第に蔵人所の職事によって行われるようになった。