TOKYO -- Ensuring stable Imperial succession is an urgent task for the government as the number of Imperial heirs decreased from four to three after Emperor Naruhito ascended to the Imperial Throne on May 1.
The government of Prime Minister Shinzo Abe will launch full-scale debate on the issue as early as autumn after a series of enthronement-related ceremonies conclude.
However, opinions will certainly be divided over whether to maintain the current system limiting those who are qualified to accede to the throne to male members of the Imperial Family in the male line.
Besides new Emperor Naruhito, Imperial Family members present at the "Kenji-to-Shokei-no-gi" ritual were Crown Prince Akishino, who is first in line to the throne and Prince Hitachi, who is the younger brother of Emperor Emeritus Akihito and third in line to the throne. The move followed the precedent of allowing only male adult members of the Imperial Family to attend the ceremony in which the new emperor inherits, as proof of his accession to the Throne, the traditional properties handed down with the Throne, such as the sacred sword and jewels, and also the State and Privy seals for use in matters of state.
Six Imperial Family members besides His Majesty were present at the previous "Kenji-to-Shokei-no-gi" ritual in 1989 when Emperor Akihito ascended to the throne.
Of seven younger members of the current Imperial Household, 12-year-old Prince Hisahito, who is second in line to the throne, is the sole male member.
In 2005, a panel of experts under the administration of then Prime Minister Junichiro Koizumi released a report recommending a review of the current system limiting Imperial heirs to male offspring in the male line.
Noting that nearly half of successive emperors were offspring of concubines, the report pointed out that conditions for securing Imperial succession by male members in the male line are being lost because of changes in the public's ethical values and social trends over child birth.
The panel estimated changes in the number of Imperial heirs on the assumption that there were five male members of the Imperial Family in the male line. Based on the 2004 total fertility rate -- the average number of children a woman bears in her lifetime -- of 1.29 and the assumption that the chance of the birth of boys was 50 percent, the panel estimated the number of male members at 2.08 in the generation of the five members' grandchildren and 1.34 in the generation of their great-grandchildren.
The report then concluded it was "extremely difficult" to maintain Imperial succession by male members of the Imperial Family in the male line.
Warning that any system that is affected by haphazardness cannot be considered stable, the report recommended that female members of the Imperial Household and those in the female line be allowed to ascend to the Imperial Throne.
However, with the birth of Prince Hisahito in September 2006, the possibility that Imperial succession by male members in the male line will be cut off was eliminated at least temporarily. As a result, calls urging that female members and those in the female line be allowed to accede to the throne lost momentum.
In 2012, the government of then Prime Minister Yoshihiko Noda summarized points of contention in discussions on Imperial succession, including allowing female members to establish Imperial Family branches to remain in the Imperial Household after marriage.
Under the current situation, however, Prince Hisahito, who is the only Imperial heir in the younger generation, and his future spouse would be under excessive pressure to have male offspring. Moreover, of six female members of the Imperial Family in the younger generation, five including 27-year-old Princess Mako and 24-year-old Princess Kato in the Akishino family, have already reached adulthood. They will leave the Imperial Family after marriage, which would leave Prince Hisahito as the sole member of the Imperial Family in the younger generation.
Nevertheless, the Abe administration is negative about discussing the issue. In an article he contributed to a monthly magazine in February 2012 when the ruling Liberal Democratic Party was an opposition party, Abe voiced clear opposition to allowing those in the female line to accede to the throne.
In the article, he pointed out that such a move would fundamentally overturn the tradition of Imperial succession that has lasted for 125 successive generations. He then insisted that the offspring of those who left the Imperial Household under the rule of Allied Powers shortly after the end of World War II be allowed to return to the household.
However, after returning to power, Prime Minister Abe admitted in a Diet session that such a move could be difficult, saying, "There's a possibility that all those subject to such measures could refuse to comply."
At an April 19 meeting of the Japan Conference, a conservative organization, former National Public Safety Commission Chairman Keiji Furuya, who is close to Abe, said, "It's important to ensure that the public understands the long history of Imperial succession by male members in the male line."
At his first news conference in the Reiwa era on May 1, Chief Cabinet Secretary Yoshihide Suga stopped short of clarifying the government's stance toward the issue.
"While bearing in mind that Imperial succession by those in the male line has been maintained, it's necessary to have cautious and detailed discussions on the issue," he said. "We'll do our best to make sure that a series of ceremonies relating to the enthronement will be held without any mishaps, and then consider the issue (of Imperial succession)."
(Japanese original by Takenori Noguchi and Minami Nomaguchi, Political News Department)