Although the media and insatiable public curiosity can expose the private secrets of superstars, the Imperial family remains largely out of view.

Magazines and tabloids try to cover the little information available about the royals, especially Crown Princess Masako and her stress-related illness, but criticism of the family is still a taboo among most Japanese. Despite this, foreigners do not consider the Imperial family off limits and often compare its situation with that of Western royalty.

The following are basic facts about the emperor system and the Imperial family:

The Imperial family is said to be the world’s oldest hereditary monarchy. When did it start?

Legend has it the first emperor was Jimmu, whose reign started in 660 B.C. Succeeding monarchs are believed to be his descendants, but most modern scholars question the existence of at least the first nine emperors. Emperor Sujin is the first many agree might have actually existed, in third or fourth century. Emperor Akihito, the oldest son of the late Emperor Hirohito, is counted as the 125th since Jimmu.

What kind of roles did the emperors play in history?

Despite their long existence, emperors wielded actual political power only in ancient times, as warlords and aristocrats, generally those with direct access to the Imperial family, ruled the country most of the time up until the Meiji Era started in 1868.

The Meiji Constitution greatly strengthened the Emperor’s political position, but his actual power, despite his being revered as “a living god,” was rather limited under the prewar and wartime constitutional monarchy. In the runup to the war Japan waged in the first half of the 20th century, Emperor Hirohito, posthumously called Showa, was basically used by strong elements in the military that effectively controlled the nation.

Under the current Constitution, the emperor is designated as “the symbol of the State and the unity of the people” with no political power. To maintain this neutrality, the emperor is not allowed to engage in political activities, and members of the royal family do not have the right to vote.

Who qualifies as a member of the Imperial family and how many are there?

Following Japan’s defeat in World War II, the Allied Occupation forces greatly reduced the assets, privileges and government budgets for the emperor and his relatives. As a result, 51 relatives of Emperor Hirohito, or 11 families, renounced their Imperial status in 1947.

Under the postwar Imperial House Law, only the brothers and children of Emperor Hirohito, as well as their wives and descendants, received Imperial family status. As of now, the family numbers 23, including Emperor Akihito. Current law limits succession to males, so when female members marry, they lose their Imperial status and become commoners.

Political debate once heated up over whether a woman should be allowed to ascend the Chrysanthemum Throne. Why did the debate start and what is the current situation?

The debate heated up until last year because no boy had been born to the Imperial family for more than 41 years, jeopardizing the future of male-only succession. The only child of Crown Prince Naruhito, 47, and Crown Princess Masako, 43, is Princess Aiko, 5.

Before February 2006 and with the apparent support of public opinion, then Prime Minister Junichiro Koizumi was preparing a bill to revise the Imperial House Law to allow a female on the throne. But then that month the Imperial Household Agency announced that Princess Kiko was pregnant, putting the debate on hold. The wife of Prince Akishino, the second son of the Emperor, gave birth to a boy in September.

In the past, however, there were eight reigning empresses. But their successors always went back to a male of the paternal Imperial bloodline, which is why some conservative scholars argue that the women’s reigns were temporary and that male-only succession tradition must be maintained. Some argue that former Imperial family members and their descendants should be reinstated to increase the number of potential male successors to the emperor, even though they have intermarried with the commoner population.

Until the Meiji Era, there was no explicit succession law. The 1889 Imperial House Law later stipulated only a male successor of the paternal line can assume the throne.

How are Imperial family members financed?

Laws on the economy of the Imperial family stipulate that national funds will be allocated for the upkeep of the Imperial family.

The emperor’s household, which includes Empress Michiko, Crown Prince Naruhito, Crown Princess Masako and Princess Aiko, receives a combined 324 million yen a year in living expenses.

The laws provide money to other members “to maintain their dignity as Imperial family members.” For example, the family of Prince Akishino, with three children, receives 54.9 million yen a year. Taxes are not levied on these expenses.

Recently, the private lives of Imperial family members, particularly Crown Princess Masako, have become hot topics again. Why?

According to the Imperial Household Agency, the Crown Princess has suffered an “adjustment disorder” since December 2003, and has yet to fully recover to perform her official duties. The Harvard-educated former elite diplomat is believed to have faced strong pressure to give birth to a boy and to be having trouble adapting to the rigid, tradition-bound life of the Imperial household, which, as one particularly stinging comment by her husband suggested, was trying to stifle her personality.

Her hardships have been spotlighted anew in a book about her by Australian journalist Ben Hills, who, among other things, claims the princess is suffering depression. Kodansha Ltd., which had been planning to publish the book in Japan, abruptly canceled the project after Japanese Ambassador to Australia Hideaki Ueda lodged a formal protest with the author and the publisher of the original English version. The Foreign Ministry says the book contains many inaccuracies and insults about Japan and the Imperial family.

Hills meanwhile said the ambassador did not specify which parts of the book were inaccurate, and called the protest “an outrageous attempt to censor or suppress information which is clearly in the public interest.” The book is highly critical of the role of the Imperial Household Agency “in bullying Masako,” Hills said in an e-mail to The Japan Times.