Part 1 established that the story of “126 generations of unbroken male-line succession” has never sustained itself autonomously, that it was a political construction chosen at a specific point in the Meiji era, and that sustaining it has required, each time, a new artificial supporting mechanism — the concubine system in the past, and now adoption. Part 2 builds on this to examine the legitimacy risks inherent in a reform bill that relies on bloodline requirements alone, and considers an alternative foundation of legitimacy.
Part Four: The Legitimacy Risk of Relying on Bloodline Alone
The Emperor’s Own Reported Concerns
This is not speculation; it has been reported by multiple outlets. Those close to the Emperor Emeritus are said to have held strong reservations about restoring former imperial family members, and the current Emperor himself is reported to have expressed concern about whether the adoption plan would gain public understanding. Given that the symbolic imperial system rests on public understanding and reverence, this should be understood not as a political objection but as a concern going to the very substance of the institution.
A Plan Already Judged “Extremely Difficult” in 2005
In 2005, an expert panel convened under the Koizumi cabinet concluded that a plan relying on male-line males from the former collateral branches presented problems from every angle — public understanding and support, stability, and tradition alike — and that its adoption would be extremely difficult. That a plan judged “difficult” twenty years ago is now being adopted in nearly the same form carries real weight.
A Divided Public, and an Ancestor Six Centuries Removed
An editorial in the Yomiuri Shimbun noted that the common male-line ancestor shared by the Emperor and the former collateral branches dates back to the Muromachi period, and that many citizens would likely feel uneasy at being told that someone becomes an imperial family member on the basis of a genealogy tracing back roughly six hundred years. Public opinion polls on the adoption plan remain closely split. Pushing bloodline requirements through without having secured public understanding means building into the institution, from the outset, a risk that the legitimacy of a future emperor enthroned on that basis will remain subject to ongoing public doubt.
A Historical Precedent: Disputed Legitimacy Once Led to Real Civil War
This is not a hypothetical concern. The period of the Northern and Southern Courts (1336–1392) saw a split over the legitimacy of imperial succession produce two rival courts and more than half a century of nationwide civil conflict. The conflict at the time was, at its core, a clash between competing claims to legitimate succession. The historical fact that leaving the question of “who is the legitimate emperor” unresolved led not merely to political confusion but to a resolution by force offers a concrete precedent for the risk of building disputed legitimacy into the structure of the institution itself.
Distinguishing Short-Term Political Convenience from Long-Term Institutional Risk
Confining the debate to bloodline, and avoiding the more intricate constitutional arguments around function or the theory of public acts, may be the more convenient short-term choice for individual politicians trying to get through the current Diet session. But that convenience simply defers a different, more consequential question — the medium- to long-term stability of the institution itself. What is a short-term risk-avoidance strategy for individual politicians is, for the institution as a whole, an accumulation of long-term risk. This distinction should not be lost.
Part Five: An Alternative Foundation of Legitimacy — Legitimacy Through Ongoing Relationship
What the Emperor Emeritus’s 2016 Message Showed
In his message of August 8, 2016, the then-Emperor (now Emperor Emeritus) conveyed an understanding that the symbolic position is not simply a status that exists on its own, but something that comes into being only through the accumulation of daily duties — traveling among the people, listening to their voices, standing close to their concerns. This was an important act of self-understanding by the person actually occupying the position, offered from an angle distinct from the constitutional text itself.
The Unresolved Core of Constitutional Theory: The Doctrine of “Public Acts”
The Constitution appears to divide the Emperor’s acts into two categories: “acts in matters of state” (Articles 6–7), requiring the advice and approval of the Cabinet, and purely private acts. In practice, however, acts that fit neither category — regional visits, remarks at ceremonies — have been a consistent feature of the postwar imperial institution. Constitutional scholarship remains divided over whether to recognize this “third category” as an independent one.
The position that denies public acts as an independent category (the “two-act theory”) worries that recognizing them would effectively expand the Emperor’s political influence, hollowing out the prohibition on “powers related to government” that Article 4 was meant to guard against. The position that recognizes them as independent (the “three-act theory” or “symbolic act theory”) holds that such acts follow naturally either from the symbolic position itself or from the Emperor’s standing as a public figure. That this dispute remains unresolved reflects a genuine trade-off at the heart of the institution: how far to permit the imperial institution to function, weighed against how strictly to preserve political neutrality.
Reading Article 1’s “Will of the People” Through the Lens of Function
Setting this doctrine of public acts alongside Article 1 reveals a structure that has been largely overlooked. Article 1 states that the Emperor’s position “derives from the will of the people,” but the article itself says nothing about how that will is to be sustained over time. One can read this as a one-time act of consent at the moment of the Constitution’s founding. But following the understanding the Emperor Emeritus articulated, one can also read it differently: the “will of the people” is not a one-time procedural consent, but something continually renewed through the Emperor’s daily symbolic conduct, within an ongoing relationship with the public.
Read this way, what should genuinely be at issue is not only “who satisfies the bloodline requirement,” but “how fully a given person can carry out the acts of a symbol” — a functional requirement.
Female Imperial Family Members Already Satisfy This Functional Requirement
Here lies a significant asymmetry in the current debate. Female imperial family members, born into the institution and having accumulated decades of public duties and contact with the public since childhood, more than satisfy the functional requirement — the accumulation of “acts of a symbol” that the Emperor Emeritus described. Yet they remain excluded from succession solely because they fail to meet the bloodline requirement (the male line).
Conversely, the individuals targeted by the adoption plan from the former collateral branches satisfy the bloodline requirement, but having lived as ordinary citizens for nearly eighty years, start from a position of having accumulated none of the functional requirement — the relationship built with the public over time. The current reform bill, in effect, excludes those who satisfy the functional requirement but lack the bloodline requirement, while opening a path for those who satisfy the bloodline requirement while their capacity to fulfill the functional requirement remains untested. If Article 1’s “will of the people” is read functionally, this ordering of priorities needs to be questioned from the ground up.
Conclusion
“Absolute preservation of male-line succession,” as Part 1 showed, is a story that has never once sustained itself autonomously. To preserve it, an artificial mechanism that had once operated openly within tradition itself — the concubine system — was deployed; and now that this mechanism has become unavailable under monogamy, the reform reaches instead into a method tradition had specifically prohibited — adoption — in an attempt to hold the story together. Continuing to cling to bloodline requirements while carrying this double contradiction amounts to accepting, as the Emperor himself is reported to have worried, an ongoing risk that the legitimacy of a future successor will remain exposed to public doubt.
By contrast, a foundation of legitimacy grounded in ongoing relationship — the kind the Emperor Emeritus described as “acts of a symbol,” which would extend succession to include female imperial family members — carries none of this double contradiction, and rests on an asset that cannot simply be substituted: a relationship with the public that has already been built.
The “will of the people” that Article 1 requires is not satisfied by a one-time proof of bloodline. Its true foundation lies in the relationship the imperial institution has continually built with the public over time. Bringing this understanding back to the center of the debate over imperial succession may be exactly what is needed right now.