Kyuchu sanden (the Three Shrines in the Imperial Court) (宮中三殿)
"Kyuchu Sanden" is a general term which refers to the three shrines in the Imperial Court: the Kashikodokoro (also known as Kensho), the Koreiden, and the Shinden. They are located south east of the Fukiage Imperial Gardens.
Shinto priests called shoten and female Shinto priests (or shrine maidens) called nai-shoten, who both belong to the emperor's personal servant group called shoten-shoku (literally, "the board of shoten"), purify and protect the Kyuchu Sanden all year round.
The Nikku no Gi (the rite of providing daily food offerings to the deceased), in which sake and sekihan (glutinous rice steamed with red beans) are offered, is held at 8:00 am every day served by nai-shoten at the Kashikodokoro and the Koreiden, and by shoten at the Shinden. An on-duty chamberlain from the Board of Chamberlains, the Imperial Household Agency, or a chamberlain who is told to stay at the Imperial Court to take care of affairs while the Emperor is absent to attend an event or visit another country, performs a rite called Maicho-godaihai (literally, "every morning worship on behalf of the Emperor") at 8:30 am and worships the deceased at the Kashikodokoro, the Koreiden, and the Shinden on behalf of the Emperor. Both the Nikku no Gi and the Maicho-godaihai are conducted every morning even when the Emperor is away from any public affairs due to some special reasons or the Court mourning is declared.
Shihohai (a Shinto ceremony held on New Year's Day in which the Emperor pays respect to the deities in all quarters) and Niiname-sai Festival (ceremonial offering by the Emperor of newly-harvested rice to the deities) are held at the Shinkaden, which is a shrine located near the Kyuchu Sanden, and Chinkon-sai Festival (a ceremony for the repose of a soul) is held at the Ryokiden, which is a shrine also located near the Kyuchu Sanden.
While there was renovation work on Kyuchu sanden, 'goshintai' (the object of worship in a Shinto shrine) was moved into a temporary Kyuchu sanden.
Kashidokoro, Kensho
This is a shrine to enshrine the Imperial ancestor called Amaterasu Omikami (the Sun Goddess). A divine mirror which is regarded as a mitamashiro (an object that is honored in place of a person's soul or a deity's sprit) of this goddess is enshrined, and the mirror is said to be a replica of the Yata no Kagami (which literally means "eight-span mirror," referring to one of the Imperial regalia). Sometimes it can mean the divine mirror itself. It had been enshrined in the Imperial palace since ancient times. When the Imperial Palace was in Kyoto, it was called 'Naishidokoro'. It is said that shoten and nai-shoten serve to take care of everything and they keep watching over a holy fire called 'imibi' after lighting it at this shrine.
The Kashikodokoro was in the Unmeiden Hall in the Heian period, and it has been in the Shunkyoden Hall since the Kamakura period.
This shrine is the place to hold Court rituals that date back to ancient times, including wedding ceremonies to welcome Imperial princesses such as Empress Michiko and Crown Princess Masako.
The marriage of a male Imperial family member is considered to be completed when he exits the Kashikodokoro.
It is said that they have very strict rules such as a distinction between 'tsugi' (uncleanness) and 'kiyo' (cleanness) because this place is respected as a sanctuary which should avoid any impurity.
Koreiden
The spirits of successive Emperors and the Imperial family are enshrined here. Jingikan (department of worship) was restored during the Meiji period and an attached shrine was built where the spirits of successive Emperors were enshrined. A custom called 'Kurodo,' in which successive Emperors were enshrined in the Buddhist style, had been succeeded at Court since the Heian period, but this was abolished in accordance with the above event.
As the Jingikan was demoted to the Jingisho (Ministry of Divinities), the Koreiden was transferred to the Imperial Palace in September 1871, and it was then called 'Kobyo' (Imperial mausoleum) together with the Kashikodokoro (Kensho). In 1878 the spirits of the Empresses and the Imperial family were enshrine together. A spirit of an emperor or an Imperial family member is moved to the Koreiden to be enshrined together with spirits of other emperors and Imperial family members one year after his or her death. The Spring Korei-sai Festival is held on Vernal Equinox Day and the Autumn Korei-sai Festival is held on Autumnal Equinox Day every year.
Shinden
Amatsukami (god of heaven) and Kunitsukami (god of land) were enshrined in the palace.
Jingikan was restored during the Meiji period (later called Jingisho) and an attached shrine was built where eight gods were enshrined in Hasshinden (eight shrines) during the time of the gods of heaven and earth from ancient times under the Ritsuryo system (a system of centralized government based on the ritsuryo code). In 1872, as rituals of the Jingisho were moved to the Imperial Court, the Hasshinden was also transferred to the Imperial Court to enshrine the eight gods with Amatsukami and Kunitsukami, and this shrine's name was changed to Shinden.