At least 120 people are planning to file a lawsuit to stop the Japanese government from using taxpayers' money for rituals to mark the enthronement of a new emperor next year, members said Thursday.

The citizens, including members of Christian groups and Buddhist monks, aim to file the suit with the Tokyo District Court in early December, claiming that funding what they deem as religious ceremonies out of public coffers violates the constitutional principle of separation of religion and state.

It is believed to be the first suit of its kind filed over Crown Prince Naruhito's ascent to the Chrysanthemum throne on May 1, a day after his father Emperor Akihito abdicates as the first Japanese living monarch to do so in 200 years.

(Crown Prince Naruhito pictured before leaving Tokyo Station by shinkansen bullet train for a visit to Yamagata Prefecture)[Pool photo]

Similar suits had been filed against the state when the now 84-year-old emperor was enthroned in November 1990 after his father Emperor Hirohito died the year before.

The government also plans to hold the enthronement ceremony for the 58-year-old eldest son of Emperor Akihito as a state act on Oct. 22, 2019, and "Daijosai" as an imperial event between Nov. 14 and 15, following the examples 30 years ago.

The plaintiffs-to-be say the ceremonies are clearly religious as they use the three sacred emblems of the imperial family and stick to forms of imperial Shinto. They expect more suits to follow.

While all suits filed over the previous enthronement rites were rejected by courts, the Osaka High Court's ruling in March 1995 said it cannot deny the suspicion that they violate the constitutional principle of separation of religion and state.

Koichi Yokota, a constitution expert and honorary professor at Kyushu University, said, "The enthronement ceremony itself has numerous problems from the standpoint of the constitutional principle of separation of religion and state and sovereignty of the people," citing lack of sufficient constitutional reviews on the pre-war era rituals.

But he said the planned suit is expected to face a high hurdle as courts have always rejected suits filed over the constitutionality of the matter from the standpoint of taxpayers.

In contrast, Isao Tokoro, professor emeritus at Kyoto Sangyo University specializing in the history of the formation of Japanese laws, said how to fund the ceremonies was decided after thorough debate held upon the previous occasion and they are constitutional.

"The Constitution itself states the heredity of the imperial throne, and I believe Japan should hold a ceremony and ritual for passing down that special status and role in a regal manner," he said.