Shishinden Hall (Hall for state ceremonies) (紫宸殿)

The Shishinden Hall was a main hall where ceremonies like the Emperor's genpuku (attaining manhood), investiture of the Crown Prince, and Sechi-e (seasonal court banquets) were held, in the Imperial Palace which was the Emperor's private place. In comparison to Seiryoden (literally, "Limpid Cool Hall," an imperial summer palace) where the Emperor usually resided, the Shishinden Hall was used for more official purposes.

In and after the middle of the Heian period, since Daigokuden (Council Hall in the Imperial Palace), the main hall of Daidairi (the Greater Imperial Palace), was ruined, the Shishinden Hall came to be used as a place to hold important events such as Sokui no rei (ceremony of the enthronement) and Daijo-sai festival (a festival to celebrate the succession of an emperor). After catching fire in the Kamakura period, the Imperial Palace was never rebuilt; however, the Shishinden Hall was rebuilt as satodairi (a temporary palace) which was a temporary Imperial Palace, and the present-day Kyoto Imperial Palace (this was also satodairi originally) has a Shishinden Hall that was built in 1855 in accordance with an ancient rite.

Sakon no Sakura (the Cherry Tree on the left) and Ukon no Tachibana (the Mandarin Orange of the right)
A cherry tree planted on the east side and a mandarin orange tree planted on the west side in the southern garden of the Shishin-den Hall are called Sakon no Sakura and Ukon no Tachibana, respectively because Sakonefu (Left Division of Inner Palace Guards) and Ukonefu (Right Division of Inner Palace Guards) were deployed near each tree. It is said that a plum tree had originally been standing where Sakon no Sakura was planted, and the plum tree was replaced with a cherry tree because it died from being dried out.
Jinsho (camp) of Sakonefu was located at Konro (roofed corridor with open sides) connecting to Giyoden (storeroom), and was called 'Sakone no jin.'
Sakone no jin substantially played a central part in the affairs of state during the golden age of regency because Court Councils (called "Jingi" (Jin no sadame, or the ancient cabinet council) because councils were held at Jinsho, and also called "Jogi" because it was allowed to bring staff (stick; indicating "Jo" of Jogi) which were chaired by Sekkan (regents and advisers) were held frequently. The Court Council was also held at the 'Ukone no jin' under Higashi-bisashi (Eastern eaves) of kyoshoden (a building in the Imperial Palace precincts) infrequently, and was drawn in the "Nenju Gyoji Emaki" (Picture Scrolls of Annual Functions) under the title of 'Ukone Jinza' (Court Council held at Ukone no jin).