Ever since the capital was moved to Heian, Kamomioya Shrine (Shimogamo Shrine) has been highly revered by both the Imperial Court and clan members as the deity protecting the royal palace. Its annual festival, the Kamo Festival, also boasts the status of an imperial festival. From the time of Emperor Saga in the early Heian period, unmarried princesses or queens served the Kamo deity as "Saio" (prefectures), similar to the "Saigū" (Saigū) of Ise Grand Shrine, and lived in a Saiin (hospital) called "Sainomiya."

The history of the Kamo Saio spans 35 generations and approximately 400 years, from the first princess, Princess Achiko, daughter of Emperor Saga in the early Heian period, to Princess Reiko, daughter of Emperor Gotoba in the Kamakura period. Many of the Saio were talented women, and as the Saio in Murasakino was close to the Imperial Palace, many courtiers gathered at the Saio's residence, Itsukinomiya, where poetry gatherings, art contests, and music performances were held. Itsukinomiya is said to have had a great influence on court ladies and nobles, especially on Murasaki Shikibu and Sei Shonagon, and was a major cultural salon that surpassed the imperial court.

Shimogamo Shrine rebuilt the main shrine in the grounds of Tadasu-no-Mori Forest as part of the 34th Shikinen Sengu project to enshrine the spirits of these 35 generations of Saio in the "Kamo Saiin Sacred Spirit Shrine." This was an opportunity to commemorate the achievements of the Saio and the significance of the existence of "Itsukinomiya," and to reaffirm the beautiful Japanese traditions and culture that the Saio created.

By doing so, we aim to inspire ambitious women living today to develop rich human relationships while respecting the courtesy between people and each other, and between people and nature, and to improve the minds and skills necessary to live beautiful and intelligent lives.We also hope to nurture the next generation of women who will lead the way.We have therefore established the Kamo no Itsukinomiya Commemoration Society.