Significant contributions to the literature of Japan were created in the Kōkyū during this period: works such as The Tale of Genji by Murasaki Shikibu, The Pillow Book by Sei Shōnagon, and many anthologies of waka poems.

For example, in 806, Emperor Heizei elevated the former Fujiwara no Tarashiko (藤原帯子) (?-794), also known as Taishi, by giving her the Imperial title of Kōgō or empress.

[3] Many of the court ranks which were not defined in either the Taihō or Yōrō Codes have been in continuous use in the centuries following the early Heian period.

[5] The origin of the current Imperial Household Agency can be traced back to the provisions on the government structure which were put into effect during the reign of Emperor Monmu.

[6] There were specific Daijō-kan officials within this ministry structure whose attention was focused primarily on the women of the Imperial household.