Tradition vs. change: Japan’s imperial succession debate intensifies

In Japan, an issue that “should never be politicized” is becoming a political issue. Under current law, only three male members of the imperial family are eligible to succeed to the throne, and the risk that the family could one day cease to exist has begun to seem increasingly real.

For decades, the nation’s government has postponed action. This week, however, Prime Minister Sanae Takaichi’s administration approved and submitted a bill to the Diet to revise the Imperial House Law, with the aim of enacting it during the current session and stabilizing the line of succession.

For foreign observers, the debate over amendments to the Imperial House Law may not be easy to understand. From the outside, Japan may appear unchanged regardless of who serves as emperor. After all, in Japan — a democratic constitutional monarchy — the emperor, as in other monarchies, is the “symbol of the state and of the unity of the people,” a monarch who “reigns but does not rule” and holds no political authority. Nevertheless, heated debate is unfolding in Japan with no sign of subsiding.

This should not be dismissed as merely a technical issue. Depending on how the matter is resolved, it could shape the nation’s future. Why have the proposed amendments become such a major issue now? Why is there likely to be no female monarch? For readers unfamiliar with Japan’s imperial system, I hope to explain this sensitive issue and its implications as clearly as possible.

There are two key points in the proposed amendments. The first is the retention of imperial status by female members of the imperial family after marriage. This would revise Article 12 of the current Imperial House Law, which stipulates that a female member who marries a commoner loses her imperial status, to allow women to remain in the imperial family after marriage.

The second is the adoption of male-line descendants from former imperial families. This proposal would create an exception to Article 9, which prohibits adoption by members of the imperial family, allowing unmarried male-line descendants from the 11 former imperial families — who left the household after World War II — to become members of the imperial family.

Historical legacy

For at least the past 1,500 years, the Japanese imperial system has been dominated by male-line succession. Although there have been female emperors, the tradition of patrilineal succession has been maintained. This is often described as the world’s longest continuous dynastic line and a significant historical legacy.

At the same time, amid the trend toward gender equality in modern society, many royal houses — particularly in Europe — allow female monarchs and rules requiring male-line succession do not exist. Exceptions are found mainly in some monarchies and emirates in the Middle East, particularly in Arab countries, though these are not representative of broader global trends.

Popular princess

The difficulty lies in the fact that a large majority of the Japanese public considers the daughter of the emperor and empress, Princess Aiko, to be a suitable candidate for the throne. Under current law, the first in line is the emperor’s younger brother, followed by his son. As the emperor’s daughter, the princess has no right to the throne.
However, as the daughter of the emperor and empress, she has received an education befitting her status and enjoys a strong public reputation.

Public opinion polls show that support for a female or an emperor descended through the female line is high. A recent Kyodo News poll found that about 90% of respondents support a female emperor and about 84% support an emperor descended through the female line. This support is often attributed to public admiration for the princess. By contrast, male members of the imperial family who hold succession rights do not always enjoy the same level of popularity.

Another factor complicating the issue is how it is framed in parts of the Japanese media. For some political commentators, whether to maintain male-line succession or recognize female and matrilineal emperors is not merely a question of institutional design. It is also tied to party dynamics, including relations between the Liberal Democratic Party and the Japan Innovation Party, as well as internal divisions within the LDP.

Because the issue could affect the stability of Prime Minister Takaichi’s administration, it has received extensive coverage.

Opinions are divided among those in the political arena. Traditional conservatives argue that maintaining patrilineal succession is essential to preserving the imperial family’s historical legitimacy, and they strongly support adopting male descendants from former imperial families.

In contrast, moderates and liberals oppose this approach, arguing that the debate over female and matrilineal emperors should not be ruled out. They also question whether the public would accept bringing in descendants of former imperial families — who have lived as private citizens — as members of the imperial family.

Public opinion

As noted, opinion polls show strong support — often between 70% and 80% — for female emperors and matrilineal succession. However, views are more divided on specific proposals.

For example, regarding whether the spouses and children of female imperial family members who remain in the household should also be considered members of the imperial family, one poll found 52% in favor and 35% opposed, suggesting no clear consensus.

Opinion is also split on adopting male-line descendants from former imperial families. A Yomiuri Shimbun poll showed 49% in favor and 37% opposed, while an ANN poll found support below 50%.

Readers may ask for my own view. As a direct male-line descendant of Emperor Go-Toba — the 82nd emperor, who attempted to overthrow the Kamakura shogunate in 1221, was defeated and exiled to the Oki Islands — I refrain from comment.

That said, while maintaining male-line succession may have been straightforward in earlier centuries and until 1945, in the 21st century it is far more difficult — even within ordinary families, let alone the imperial household.

So what are the views of the general public? They appear highly engaged but ultimately ambivalent. Whether the throne passes to the current princess or, in the future, to the son of an adopted male-line descendant, most Japanese people would likely accept the outcome.

That said, Emperor Naruhito recently expressed hope that any revisions to the Imperial House Law would be “such that they can gain the understanding of the people.” If so, it raises a fundamental question: What should the imperial family look like in a system based on public consensus?