Japan keeps male-only imperial succession, opens door to adopted royal heirs

Tokyo,UPDATED: Jul 17, 2026 13:52 IST

Japan's parliament has passed a major revision to the Imperial House Law, keeping in place the rule that only men from the paternal line can become emperor. The changes also allow the adoption of distant male royal relatives to father future heirs, while letting princesses keep their royal status after marrying commoners.

The move has revived debate over the future of Japan's monarchy, which is shrinking and ageing quickly. Emperor Naruhito's daughter, Princess Aiko, is popular with the public, but she cannot succeed because she is a woman. Under the current order of succession, the line goes to Naruhito's younger brother, Crown Prince Akishino, then to his 19-year-old son Prince Hisahito, and then to the emperor's 90-year-old uncle, Prince Hitachi.

Supporters of the revision say it protects the imperial bloodline. Prime Minister Sanae Takaichi and other conservatives have said the male bloodline is "the only source of the emperor's authority and legitimacy". Under the Imperial House Law, while an emperor's mother may be a commoner, only boys born to men with royal blood can inherit the throne.

The revised law is meant to reinforce that principle by allowing unmarried male descendants aged 15 or older from distant imperial branches, but only from the paternal line, to be adopted into the royal family. Imperial Household Agency official Yoshimi Ogata told parliament that 51 members from 11 branch families lost their royal status in 1947 to reduce the monarchy's post-war financial burden. Ogata said those people are at least 36 generations removed from Naruhito because they split from a common male-line ancestor 600 years ago.

The other main change allows princesses to remain royals after marrying commoners, though their husbands and children will not be recognised as members of the imperial family. Five unmarried princesses, including Aiko and her cousin Kako, may be affected. Aiko's cousin Mako gave up her royal status and moved to New York after marrying her college boyfriend, now a lawyer.

Critics say the changes are aimed at blocking female monarchs. "It's a declaration to prevent female monarchs ... and to defend the male-lineage at all costs," said Hideya Kawanishi, a Nagoya University expert on monarchy. "They cannot say it's male chauvinism, so they call it tradition." Japan has had eight female monarchs, the last being Empress Gosakuramachi, who ruled from 1762 to 1770.

The male-only rule was first set out in the 1890 Imperial House Law, during a period when Japan promoted patriarchal systems, and it was largely carried into the 1947 law. Critics say the system is no longer workable. Only five of the 16 adult members of the imperial family are men, and there are no children. Hisahito was the first male royal baby born in four decades. Historians say the system worked in the past partly because concubines produced about half of Japan's emperors until that practice ended about 100 years ago under Emperor Taisho.

There were protests on Friday from people who saw the changes as an attempt to rule out Aiko and preserve a patriarchal system. Chizuko Ueno, a feminist scholar, wrote: "It's very ironic that the first female prime minister herself is the leading proponent of the obsession with male-succession." She also said the measures "treat male royals as stallions and put female royals under pressure as childbearing machines" to produce male offspring. After Aiko's birth, her mother Empress Masako, a Harvard-educated former diplomat and a commoner, developed a stress-induced mental condition amid criticism that she had not produced a male heir.

Former Imperial Household Agency chief Shingo Haketa told Kyodo News that, because of the male-only succession rule and the removal of princesses who marry commoners, the monarchy after Hisahito is "extremely unstable". A 2005 government proposal to allow female monarchs was dropped after Hisahito was born. Crown Prince Akishino, now 60 and only six years younger than Naruhito, has reportedly said he would be too old to serve. Kawanishi said Hisahito, any adoptees and their future wives would face heavy pressure to have sons.

The proposal to bring back former royals has also drawn criticism. Cartoonist Yoshinori Kobayashi, who supports Aiko's succession, asked: "Who wants the son of an adoptee who nobody knows to be emperor instead of Aiko?" Former royal Asahiro Kuni, whose family lost its status when he was three, told TBS: "I wonder if anyone would raise a hand," adding that it would be cruel to ask a 15-year-old to change the course of his life. He said he would advise his family to refuse if asked: "You are asked to sacrifice your life for the happiness of the people. I can't tell my family to choose such a difficult life." He also backed female monarchs.

Public support for Aiko remains strong. "The emperor is a symbolic figure, and I don't see why women cannot serve in the role," said Junichiro Tsujimaru, 78. Yoshio Iwase, also 78, said Aiko, as the emperor's daughter, is the rightful successor, adding: "I think it's fine because there used to be female emperors in the past." There are also concerns that the government's push could affect the legacy of former Emperor Akihito, who sought to bring the monarchy closer to the public and is reported to support Aiko's succession. Naruhito said in June that he hoped the debate would lead to a conclusion that "will gain understanding of the people".

Alongside the imperial law revision, Japan also passed a new law banning desecration of the national flag, another measure backed by Takaichi and criticised by opponents. The wider debate over the monarchy now centres on whether preserving a male-only line can keep the institution stable, even as Princess Aiko remains ineligible and the imperial family continues to shrink.

With PTI Inputs

- Ends