Japan passes law cementing male-only imperial succession

Japan’s Diet approved amendments to the 19th-century Imperial House Law, confirming that only males of the paternal line may inherit the Chrysanthemum Throne. The changes also permit princesses to keep their royal status and continue official duties if they marry commoners, while allowing the adoption of distant male relatives to expand the pool of potential heirs.

Under the revised rules, Emperor Naruhito’s 24-year-old daughter, Princess Aiko, remains ineligible for succession, and the line of succession moves to the emperor’s younger brother, Crown Prince Akishino, and his 19-year-old son, Prince Hisahito. The next in line after them is the emperor’s 90-year-old uncle, Prince Hitachi.

Prime Minister Sanae Takaichi, a supporter of the male-only rule, said the measure safeguards “the only source of the emperor’s authority and legitimacy.” Imperial Household Agency chief Buichiro Kuroda said the agency will support the family’s activities in line with the revisions.

Critics, including scholars and feminist commentators, argue the law entrenches gender discrimination and could further shrink the already small imperial family, which has no children and only five male adults among its 16 members. They note that Japan has had eight female monarchs in its history, the most recent being Empress Go-Sakuramachi in the 18th century.

The legislation also introduces a provision allowing unmarried male descendants of distant collateral branches—who are at least 36 generations removed from the current line—to be adopted into the imperial family, a step intended to broaden the pool of male heirs.

Public opinion remains divided, with some citizens expressing support for a female successor, while others uphold the tradition of male succession. The government’s move comes alongside a new law criminalising desecration of the national flag, a measure championed by Prime Minister Takaichi.