Emperor Naruhito of Japan: Who will be his successor?

Japan's parliament has amended the Imperial Household Law. On July 17, the reform passed the upper house. It is the first intervention in the regulations since the 1940s, preceded by a debate lasting more than 20 years. The core of the reform: male descendants of former noble branches shall be able to return to the imperial family through adoption. Princess Aiko (24), the only child of the current imperial couple, remains excluded from the line of succession.

Eleven branches qualify for the new adoption rule, which applies to unmarried men over 15 years of age. The descendants in question had lost their titles after Japan's defeat in World War II. Adopted candidates themselves would not be eligible for the throne, but their descendants would be.

In addition, women from the imperial household may now retain their status even after marrying a commoner and no longer have to leave the family. Princess Mako (34), the emperor's niece and eldest daughter of Crown Prince Akishino (60) and Crown Princess Kiko (59), still had to renounce her royal titles in 2021 and left the imperial family to marry her college sweetheart Kei Komuro. They later moved to the United States, where they work as lawyers and had their first child in May 2025.

Still No Empress Possible

Women remain excluded from the line of succession - unlike many European monarchies, which have long since abandoned male primogeniture.

So nothing changes for Princess Aiko, the only child of the imperial couple Naruhito (66) and Masako (62), who have reigned since 2019. She cannot succeed her father, even though polls regularly show a large majority of Japanese people wish for exactly that.

Only Three Heirs Under Current Rules

The imperial household currently has only 16 members. Who can succeed the 66-year-old Naruhito to the Chrysanthemum Throne is limited under the old legislation.

First in line is his younger brother Fumihito, better known as Crown Prince Akishino, who is 60 years old. Behind him follows his 19-year-old son Hisahito, the only male descendant of the younger generation. As the third candidate, there is the emperor's uncle - Prince Hitachi, who is already 90 years old.