On Thursday evening, Japan's Emperor Naruhito will perform the Daijosai rite, a key imperial succession ritual for his enthronement, in a temporary Shinto shrine compound where he will make offerings to ancestors and to deities of heaven and earth.

The main part of the ritual, which runs through the early hours of Friday, will be held behind closed doors, but here is a brief explainer of what happens:

Q: What is the Daijosai?

A: The Daijosai or the Great Thanksgiving Ceremony dates back to at least the late seventh century. It is performed by the new emperor in the fall of the year of his formal enthronement, replacing the annual imperial harvest festival known as Niinamesai. The main rite, Daijokyu no gi, will be held on Nov. 14 and 15.

Q: Where will it be held?

A: The ceremony will be held in a temporary Shinto shrine compound called the Daijokyu, which was specially built in the East Gardens of the Imperial Palace grounds for the Daijosai. The shrine complex, composed of nearly 30 buildings occupying about 6,500 square meters, will be displayed to the public free of charge between Nov. 21 and Dec. 8 before being dismantled.

(Then Emperor Akihito during Daijosai in November 1990)

Q: How will the emperor conduct the main rite?

A: The emperor will sit in the direction of Ise Jingu, a shrine in Mie Prefecture that is said to enshrine the Shinto sun goddess Amaterasu, the mythical ancestress of the imperial family. He will offer newly harvested rice and grain to imperial ancestors and deities of heaven and earth. The emperor will also partake of the grain, and pray for peace and abundant harvests for the country and its people. The main part of the ritual will not be disclosed to the public.

Q: What are the offerings and how are they chosen?

A: As offerings, each of Japan's 47 prefectures delivered three to five items of specialty produce, such as vegetables, fruit and seafood, which were bought by the Imperial Household Agency. The rice for the ritual was cultivated in two rice paddies in the country's east and west with the locations determined by divination using turtle shells. Special hemp fabric from Tokushima Prefecture and silk cloth from Aichi Prefecture were also provided.

Q: What happens to the offerings afterward?

A: In the past, the offerings were buried underground after the ceremony. The Imperial Household Agency said it has decided this time that the food offerings will be consumed.

(Ceremony in Nantan, Kyoto Prefecture, on Sept. 27, 2019, to harvest rice for use in the Daijosai)

Q: Why is the ceremony controversial?

A: The Shinto ceremony is funded by the government, which critics say contravenes the constitutional separation between state and religion. The government argues the public nature of some imperial succession ceremonies like the Daijosai warrants them being state-financed.

Q: How much does the Daijosai cost?

A: The Daijokyu temporary compound was built at a cost of 957 million yen ($8.8 million) with its size reduced by 20 percent compared with the one constructed for the previous ritual in 1990 to cut costs. The total building expenses for the rite including costs to dismantle the compound and restore the area to its original state are expected to reach 2.44 billion yen. The government plans to recycle the wooden building materials for parks and disaster-prevention facilities.

(The temporary Daijokyu halls in November 1990)

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