Japan’s most popular royal, 24-year-old Princess Aiko, is at the centre of a growing debate over the country’s male-only imperial succession law, with a recent poll showing that 72% of Japanese respondents support the idea of a woman becoming emperor.
Aiko, the only child of Emperor Naruhito and Empress Masako, has won public admiration for her composure, dignity and grace. Her face frequently appears on magazine covers, while fans seek out her outfits online and crowds gather at official engagements to catch a glimpse of her.
Despite her popularity, Aiko is legally barred from ascending the Chrysanthemum Throne, prompting growing questions about why women remain excluded from the succession as Japan’s imperial family continues to shrink.
Male-only succession faces growing scrutiny
Under a law introduced in 1947, women cannot ascend Japan’s imperial throne. The legislation is rooted in the Meiji-era Imperial House Law introduced in 1889.
The imperial family has fallen from 30 members three decades ago to just 16 today, only five of whom are men. The dwindling number of male royals has intensified concerns about the long-term survival of the succession system.
A poll conducted by the Mainichi Shimbun newspaper in April found that 72% of respondents supported a female emperor, while just 10% opposed the idea. Support for reform cuts across political affiliations, adding to pressure on the government to reconsider the rules.
The current line of succession comprises only three men: Emperor Naruhito’s younger brother, Crown Prince Akishino; Akishino’s son, Prince Hisahito; and the emperor’s 90-year-old uncle, Prince Hitachi.
Hisahito, a 20-year-old university student, was the first male born into the imperial family in four decades. If he does not have a son, the male line of succession could end within a generation.
Previous governments have considered changing the law to allow women to inherit the throne. However, opposition from conservative lawmakers and Hisahito’s birth in 2006 brought an earlier reform debate to an abrupt halt.
Government moves to preserve male-line succession
Prime Minister Sanae Takaichi and her conservative allies have pushed through amendments intended to secure the male-only succession for future generations, drawing criticism from supporters of reform.
The changes, which are due to take effect later this month, will allow female members of the imperial family to retain their royal status after marrying commoners. They will also permit male-line descendants from 11 collateral branches of the imperial family, which left the royal household after the Second World War, to return.
Under the arrangements, a distant male relative could be adopted into the imperial family if he is unmarried and aged over 15. If he later marries and has a son, the child would become eligible to enter the line of succession.
During parliamentary discussions, Takaichi said the imperial line’s uninterrupted male-line descent over 126 generations was fundamental to the emperor’s authority and legitimacy. She has also maintained that the amendments are intended to ease the succession crisis rather than resolve the debate over female emperors.
Makoto Okawa, a professor at Chuo University in Tokyo who specialises in imperial lineage and succession, said the amendments clearly pointed towards preserving the male line.
The dispute has also drawn international attention. In 2024, the United Nations Committee on the Elimination of Discrimination against Women urged Japan to allow a female emperor. The Japanese government rejected the intervention as ‘regrettable’ and ‘inappropriate’, describing imperial succession as a matter of fundamental national identity.
Aiko’s popularity adds to pressure for reform
Aiko’s growing popularity could intensify calls to reconsider the succession rules, amid public unease over excluding a potential successor solely because she is a woman.
Okawa said many Japanese people had watched Aiko grow up and admired the composure and dignity she displayed during diplomatic and other official engagements.
He added that many saw her as embodying Emperor Naruhito’s understanding of the emperor’s role as a symbol of the nation who remains close to the people.
Jin, who runs an Instagram account dedicated to Aiko, said the government had disregarded widespread support for changing the male-only succession law.
She believes Aiko is qualified to succeed her father, describing her character and dignity as being of the highest calibre and saying she was worthy of serving as a symbol of Japan.
Aiko would not be the first woman to ascend Japan’s throne. The country has had eight female monarchs, although their reigns were intended to maintain the imperial line until a male heir was born. The most recent was Empress Go-Sakuramachi, who ruled from 1762 to 1770.
Members of the imperial family are prohibited from commenting on politics, but their public remarks have reflected calls for discussions about the institution’s future.
At a press conference in June, Emperor Naruhito said he hoped parliamentary discussions on securing the number of imperial family members would gain public understanding.
Akishino offered a more direct observation, telling reporters that society should continue to progress and that the imperial family’s duty was to respond to society’s needs.
‘I do not think there are any differences between women and men,’ he said.
