Japan's Parliament has voted to maintain a male-only succession for the imperial throne, revising an Imperial House Law dating back to the 1800s. The decision effectively blocks Princess Aiko, Emperor Naruhito's 24-year-old daughter, from ever ascending to the Chrysanthemum Throne.
Lawmakers passed the revisions despite warnings from experts that restricting succession to men in the paternal line will accelerate the decline of Japan's aging and shrinking imperial family. To address the dwindling number of eligible heirs, the changes permit the adoption of distant male relatives into the imperial family to father future successors. However, strict rules remain in place to ensure the throne is inherited by men with royal blood.
The revised law also allows princesses to retain their royal status even after marrying commoners, a change from previous regulations.
Under the current law, Emperor Naruhito's younger brother is next in line to the throne, followed by his 19-year-old nephew, Prince Hisahito, and then the emperor's 90-year-old uncle. Prince Hisahito is the only male born into the imperial family in four decades, and only five of the 16 adult members are men.
Supporters of the male-only succession, including Prime Minister Sanae Takaichi and other conservatives, argue that the male bloodline is fundamental to the emperor's authority and legitimacy. Hideya Kawanishi, an expert on monarchy at Nagoya University, stated that the decision is a "declaration to prevent female monarchs ... and to defend the male-lineage at all costs," adding that proponents frame it as tradition rather than male chauvinism.
Critics have expressed concern about the impact on the imperial family's future. Sociologist Chizuko Ueno commented that the new rules treat male royals as "stallions" and place female royals under pressure as "childbearing machines" to produce male offspring.
Japan has historically had eight empresses, all descended from the male line. The last female monarch was Empress Go-Sakuramachi, who reigned from 1762 to 1771 before abdicating in favor of her nephew. The exclusion of women from succession was first implemented in 1890 under the original Imperial House Law and was carried over into the modern law enacted in 1947, the same year Japan's constitution stripped the emperor of governing powers.
Like Britain's royal family, Japan's imperial family serves as a significant national symbol.