The Imperial Household Agency told the prime minister it is "an urgent matter" for the government to consider whether a female member of the Imperial family should be allowed to create a new family branch by maintaining her royal status after marrying outside the family, it has been learned.
The agency also told Prime Minister Yoshihiko Noda last month it is necessary to design a system to ensure stable succession to the Imperial throne, government sources said.
Article 12 of the Imperial House Law stipulates that female members of the Imperial family cannot form a family branch--they lose their royal status upon marriage, unless they marry the Emperor or another member of the Imperial family.
The agency is apparently proposing revisions be made to the relevant laws so female members of the Imperial family can create new branches of the family tree, according to the sources.
The Imperial family currently comprises the Emperor and 22 other members, with four of the seven male members in their 60s or older.
There are eight unmarried females in the Imperial family, including three granddaughters of the Emperor: Princess Aiko, 9, the only child of Crown Prince Naruhito and Crown Princess Masako; and Princesses Mako, 20, and Kako, 16, two of the three children of Prince Akishino and Princess Kiko.
The five other unmarried female members are all granddaughters of Prince Mikasa, brother of Emperor Showa. The eldest is 29-year-old Princess Akiko.
According to the sources, the Imperial Household Agency is concerned it will become more and more difficult for the Imperial family to perform its duties as the number of members decreases due to females marrying outside the family and losing their royal status.
Shingo Haketa, grand steward of the agency, visited Noda at the Prime Minister's Office on Oct. 5, and told him it was a matter of urgency to enable female members of the Imperial family to create family branches, the sources said.
Other officials of the agency have delivered similar communications to senior government officials, the sources said.
According to the sources, agency officials said creating a system to maintain the stability of Imperial succession is a mid- to long-term concern, considering Prince Hisahito, 5--son of Prince Akishino and Princess Kiko--is at present the only grandson of the Emperor eligible to assume the throne.
Allowing females to create family branches would also pave the way for a female to assume the throne if there is no male heir.
During the process of drawing up its constitution, the Meiji government considered making it possible for a female member of the Imperial family to take the throne. The possibility was also discussed by the Imperial Diet just after the end of World War II.
In November 2005, an advisory panel to then Prime Minister Junichiro Koizumi submitted a report that proposed female members of the Imperial family be allowed to create family branches upon marriage, and that they or their descendants be able to assume the throne.
However, after Prince Hisahito was born in September 2006, becoming the third potential heir to the throne, the government decided not submit a bill to revise the law.