Japan revises imperial succession laws, allowing readmission of former imperial branch males

Japan's Parliament on Friday approved the first major revision of the country's imperial succession laws, to address the risk that the last young male heir may not have a son.

By law, only a paternal-lineage male can become emperor in Japan. Female royals have been required to leave the imperial family when they marry commoners.

Japanese Emperor Naruhito, who acceded to the throne in 2019, and his wife, Empress Masako, have one child, 24-year-old Princess Aiko, who was born in 2001. She cannot inherit the throne under the current system.

Instead, Naruhito's younger brother, Prince Akishino (also known as Fumihito), is considered the crown prince. Akishino's son, Prince Hisahito, is second in line to the throne.

In 2005, a panel appointed by then Prime Minister Junichiro Koizumi unanimously recommended allowing female emperors and succession through the female line. The proposal was shelved after the birth of Prince Hisahito the following year eased immediate concerns.

Increasing the likelihood of a male heir

At the moment, there are only three candidates who could theoretically succeed the 66-year-old Naruhito: his brother, Crown Prince Akishino (60), Prince Hisahito (19), and Naruhito's uncle Prince Hitachi (90).

The latest changes, however, allow male members of former collateral branches of the imperial family to be readmitted. Those branches lost their imperial status after Japan's surrender at the end of World War II and their members have since lived as private citizens.

Under the new law, men from those branches can enter the family through adoption if they are at least 15 years old. The adoptees themselves will not receive succession rights, but their future male-line sons will be eligible for the throne.

Women are still not legally allowed to ascend to the throne.

Opinion polls suggest that the compromise reached by parliament — while endorsed by Prime Minister Sanae Takaichi — is unpopular with much of the wider public, who would rather see Emperor Naruhito's daughter inherit the throne.

A nationwide Mainichi Shimbun poll conducted in June found that 40% of respondents supported both a female emperor and female-line succession, while 33% supported a female emperor but opposed female-line succession. Overall, 73% supported a female emperor, compared with 6% who opposed the idea.

Rethinking imperial succession

This is the first significant revision of the Imperial Household Law since 1947, and it shows "that gender equality is not among the priorities," Sven Saaler of Sophia University in Tokyo said. "A woman on the imperial throne has been pushed even further into the distance by the legal amendment," he told Germany's dpa news agency.

An editorial in Japan's liberal Asahi Shimbun newspaper challenged statements made during parliamentary debate that male-line succession represented an unbroken 2,600-year tradition, arguing that parts of the early imperial lineage are rooted in mythology rather than verifiable history.

European monarchies increasingly adopted gender-neutral succession as women gained political rights after the two world wars, both to reflect equality and secure stable royal succession, added Asahi Shimbun.

Keiko Hongo, an emeritus professor of Japanese medieval history at the University of Tokyo, told Asahi Shimbun that Japan's former women emperors were historically significant, particularly because women were generally excluded from heading samurai families.

Hongo said the current imperial family already had sufficient legitimacy, arguing that succession through women was more natural than restoring the male line through distant relatives.

The president of the Constitutional Democratic Party, Shunichi Mizuoka, questioned the amendment on gender-equality grounds at a press conference and called for an end to male-line male succession.

Conservatives defend tradition

Supporters of the amendment reject the claim that male-line succession discriminates against women.

The conservative Sankei Shimbun supported the amendment, arguing that imperial succession had always followed the male line and was therefore not a matter of gender discrimination.

It warned against abandoning that tradition and said uncertainty remained because Prince Hisahito is the only eligible male heir of his generation.

Akira Momochi, a constitutional law professor at Kokushikan University in Tokyo, told Sankei Shimbun that the reform would help preserve traditional male-line succession.

He argued that there was no immediate need to discuss a female emperor because the succession from Naruhito through Akishino to Hisahito had already been established.

Kenichi Kawamura, a political figure and adviser to the Central Union of Japan-Korea Friendship Associations, said that allowing married female royals to remain in the family was a practical way of ensuring stable imperial succession.

He supported adoption from former imperial branches in principle but said prospective members should ideally receive royal education from childhood.

Kawamura said that, in his personal view, an "Empress Aiko" serving for one reign could be considered as an emergency measure if the male line became unsustainable, without introducing female-line succession.

"The emperor is a ceremonial figure who prays for Japan's enduring prosperity, comparable to the pope, and should remain removed from politics," he told DW.

"I hope the reform will help create a stable imperial family that is respected and cherished by the Japanese people."