The custom had been observed from the mid Heian period: at first, it was limited to the government posts at the rank of hangan (inspector [third highest of the four administrative ranks of the ritsuryo period]) and below in order to support Imperial Princes and consorts financially; later it was extended to Daijo Tenno (retired emperors), Sangu (the Empress, the Dowager Empress, the Grand Dowager Empress), and ministers (however, it was limited to jo [secretary of provincial offices] and Otoneri [royal attendant] among ministers), and the government posts granted were also extended to gon no kami (provisional governor) and suke (provincial governor) other than hangan.
平安時代中期頃から見られるが、当初は親王・女御などの生計に資するために判官以下の官職に限って給したが、後には太上天皇や三宮(后妃)、大臣などに支給対象が広げられ、支給される役職も権守や介などにも広げられた（ただし大臣は掾・大舎人に制限された）。