In the mid Heian period when annual events became organized as a part of kuji in the political affairs, the taxation system of the ritsuryo system fell apart, so the management cost of the Imperial Court including kuji became to be borne by zuryo (provincial governor) who were kokushi.
政務における公事の一環としての年中行事が整備されてきたのと同じ平安時代中期には、租庸調・雑徭を基本とする律令制の租税体系が解体したため、公事を含めた朝廷の運営費用は諸国の国司である受領が負担を請負う図式となった。