TOKYO (Reuters) - In the chill pre-dawn hours of Friday, Japan’s Emperor Naruhito emerged from a shrine compound where he had spent a symbolic night with the sun goddess from whom conservatives believe his family descends, completing the rituals of his accession.

The “Daijosai” rite, centred on the goddess Amaterasu Omikami, began soon after sunset on Thursday and is the most overtly religious of all the rituals around Naruhito’s succession after his father, Akihito, abdicated in April.

Amid flickering torchlight and chanting by priests, Emperor Naruhito emerged from behind the white curtains of the shrine at around 3:00 a.m., concluding a ceremony observed by Prime Minister Shinzo Abe and 400 dignitaries in an outdoor pavilion.

“This ritual is basically a feast involving the sun goddess and the emperor,” said John Breen, a professor at Kyoto’s International Research Center for Japanese Studies, who added that most coronations have mystical elements.

“The emperor is transformed by partaking of this feast.”

Observance of the ritual has prompted lawsuits from critics ranging from communists to Christians, who say it smacks of the militaristic past and violates the constitutional separation of church and state, as the government pays the cost of 2.7 billion yen ($25 million).

Persistent rumours have held that the emperor has conjugal relations with the goddess, a view dating from the era before World War Two, when the emperor was considered divine. Naruhito’s grandfather Hirohito, in whose name Japan fought the war, was stripped of his divinity after its defeat.

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But the government and scholars say the ritual is a meal, at which the emperor offers foods ranging from rice and millet to abalone and persimmons to the goddess in the final ceremony that seals his new status as emperor.

Preparations began months ago, with the construction of a special shrine compound within the palace grounds and, later, the harvest of rice from two fields chosen by heating a turtle shell and reading the pattern of cracks.

DINING WITH GODDESS

Soon after sunset, in scenes broadcast live on television, Naruhito was ushered through dark wooden corridors, shielded by a ceremonial umbrella and preceded by courtiers holding torches. Empress Masako followed, in 12-layered white robes.

After disappearing behind white curtains into a dimly-lit room, kneeling by the side of piled straw mats draped in white, the emperor, accompanied only by two shrine maidens, arranged offerings for the goddess on 32 oakleaf plates.

Then he bowed and prayed for the peace of Japan.

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Afterwards, they shared a meal of rice, millet and rice wine before he left the chamber. An identical ritual began in a different room around midnight.

Critics say that while a form of the ritual existed more than 1,000 years ago, its current shape dates from efforts in the late 1800s to unite Japan around the emperor.

Koichi Shin, 60 and head of a group suing to ban the ritual, cited the rite’s nationalistic underpinnings as one reason for its opposition. Another is the use of public funds.

Shin said there were fewer objections to Thursday’s event and other imperial rites than at Akihito’s accession in 1990, with less critical press coverage and fewer protests. Just 318 people sued the government this time, down from 1,700 then.

“We don’t expect good results,” Shin said. “But we think it’s important to use everything we can to get across the idea that merging religion and state isn’t good.”