Japan’s Imperial system, in which the throne has been passed down to members in the paternal line for 126 generations, is unprecedented in the world. However, it will be impossible to ensure a stable Imperial succession by continuing to expect women who have joined the Imperial family to bear sons.

Clinging to the premise that only male descendants in the paternal line are eligible to inherit the Imperial throne could jeopardise the very survival of the Imperial system.

The ruling and opposition parties have held a meeting to consider measures to secure an adequate number of Imperial family members, the second such gathering during the current Diet session.

The Centrist Reform Alliance, which had delayed consolidating opinions within the party, presented its views for the first time. It described a proposal that would allow female Imperial family members to remain in the Imperial family after marriage as a “priority measure” and called for it to be implemented as soon as possible.

In 2005, an expert panel accepted idea of a female empress, based on premise that it is difficult to maintain succession only in paternal line

Regarding a proposal to adopt into the Imperial family paternal-line male descendants of former Imperial family branches that left the Imperial register after World War II, the CRA said that this “could be institutionalised.” The wording was kept vague, reportedly because there is persistent caution regarding the adoption idea among lawmakers originally from the Constitutional Democratic Party of Japan.

Political parties such as the Liberal Democratic Party, the Japan Innovation Party and the Democratic Party for the People have supported the adoption proposal. Because the CRA did not explicitly oppose it, some people speculate that the ruling and opposition parties are close to reaching an agreement on this matter.

The LDP has taken the position that newly adopted members would not be eligible for the Imperial throne, but that sons born to them would be eligible. However, the ruling and opposition parties have not sufficiently discussed who would be eligible for the Imperial throne.

A report compiled by a government expert panel in 2021, which serves as the basis for discussions among the parties, lacks the perspective of ensuring the stable succession of the Imperial line.

The report avoided addressing what form the Imperial succession should take, saying that it was premature to consider this issue. It instead narrowed the focus to the issue of ensuring a sufficient number of Imperial family members. As specific measures, two proposals were presented in the report: allowing female Imperial family members to remain in the family after marriage, and adopting paternal-line male descendants of former Imperial family branches.

The risk of the Imperial line dying out cannot be overcome if the parties are bound by the panel’s report, which shelved measures to stabilise the Imperial succession. During the administration of then Prime Minister Junichiro Koizumi, a different government expert panel compiled a report in 2005 that accepted the idea of female and female-line emperors, based on the premise that it is difficult to maintain the succession only in the paternal line.

The fact that the parties currently supporting the adoption proposal are rushing to a conclusion without giving the 2005 report any consideration suggests that their aim is to rule out the possibility of female and female-line emperors.

It would be setting the wrong priority if the parties cling excessively to the tradition of male-only paternal line succession, at the cost of causing the Imperial line to die out. Both the ruling and opposition parties should make the survival of the Imperial line their top priority.

Published in Dawn, May 18th, 2026