Introduction: One Line of Reasoning
In July 2026, a district court in Japan handed down a ruling that read, in essence: “It cannot be found that the elementary school teachers acted in violation of any legal duty arising from their office.”
A single sentence. Behind it stood a child kicked and injured by a classmate. A child who, about four months later, wrote in her workbook, “I wish I could just die,” and received it back with a gold star and “You can do it! Fight!” scrawled beside it. Parents who asked for an investigation and were told, in effect, that the school wasn’t the police. Eight months during which the matter was left unaddressed. A later admission, by the city’s own board of education, that the school’s initial response had been inadequate. One child’s injury, the time that passed, the anger a family carried — all of that human weight is poured into this single sentence, compressed, and handed back out.
A legal professional can read a fair amount out of that one line: which line of precedent it draws on, how the organizational-response duties set out in the Act on the Promotion of Measures to Prevent Bullying are being construed, which factors were weighed and how heavily. This is possible only because the professional community shares, after years of accumulated case law, a set of unspoken interpretive conventions. It is an efficiency that exists within a closed system.
But the people whose lives are shaped by that ruling are not the professional community. They are the child who was bullied, and her parents. The coldness of the compressed sentence, set against the weight of the pain that preceded it — that gap is the doorway into everything that follows.
Bryan A. Garner’s Critique — Written for Whom?
Bryan A. Garner, the American legal-writing authority, has spent decades criticizing the way legal documents are written. His central claim is simple: contracts and judicial opinions are, more often than not, written not for the parties who actually use them but for other lawyers and judges — for a readership of peers who will read and evaluate the work. The result is documents that are needlessly opaque to the people they govern, weighed down with jargon and nested clauses. The plain-language movement has developed, in practical terms, as a correction to this misidentification of the reader.
A contract is something the parties use. A judgment is something that reshapes the lives of the parties to it. If the writer is addressing not the actual reader but an imagined peer-evaluator, something has gone fundamentally wrong.
The Critique Applies Not Only to Writing, but to Reading
Garner’s critique is usually received as a matter of style — how legal documents ought to be written. But its real reach extends further, into how a ruling’s reasoning is structured and made comprehensible in the first place — into the very architecture by which a judgment is communicated.
A judgment that is “readable” within the professional community is, in fact, simply a compressed description completed by shared tacit knowledge among professionals. The sentence “it cannot be found that any legal duty was violated” conveys some information to a professional, and nothing at all to the party concerned. Why a response the board of education itself called “inadequate” turns out not to constitute a “violation of duty” under the State Redress Act — that logical bridge is never made visible in the text of the judgment.
This is not merely a matter of plain versus opaque style. The real question is whether the reasoning process itself is presented in a form that can be independently verified, without relying on professional tacit knowledge. In a judgment based on “comprehensive consideration of all circumstances,” which factors carried how much weight, and why? Is that weighting actually shown in the text — or is it compressed into the single phrase “considered comprehensively,” with only professional intuition filling in the rest?
The phrase “taking all circumstances into comprehensive consideration” appears constantly in Japanese judgments. To a professional, it reads as the product of careful, expert weighing of every relevant factor. From the outside, it is an unmarked box: no indication of which factor received how much weight, or why the balance came out as it did. This resembles, structurally, the “black box” problem now often raised about AI decision-making — a conclusion emerges from a mass of data, but the path to it cannot be traced by a human observer. The difference is telling: an AI’s black box is criticized as a technical limitation, while a judgment’s “comprehensive consideration” is often received, affirmatively, as a mark of expertise. The very opacity becomes the source of its authority.
Lon Fuller’s “Internal Morality of Law”
To place this problem on firmer theoretical ground, the legal philosopher Lon Fuller’s concept of the internal morality of law is useful. Fuller set out a series of formal conditions that law must meet in order to function as law at all — among them, that law must be publicly promulgated and comprehensible.
This is not satisfied merely by formal publication — printing a ruling in an official gazette, delivering it in open court. It is a requirement that the person bound by the law actually be able to understand its content. If the reasoning behind a judgment can only be decoded from within the professional community, then that judgment may be formally public while substantively failing to meet this requirement of internal morality.
Fuller’s conditions are not limited to comprehensibility. They also include the absence of contradiction, a reasonable continuity that prevents law from being arbitrarily changed, and a prohibition on retroactive judgment — conditions that together amount to predictability. And here is the connection worth noticing: a failure of comprehensibility is, in substance, a failure of predictability as well. Being told one day, on the strength of precedent that only professionals can decode, that “no violation of duty is found,” feels to the party concerned almost indistinguishable from being judged after the fact by a rule one was never told about. Reasoning that cannot be understood strips the party of the very thing law is supposed to offer: a guide for how to act.
Law exists for the citizens who live under it. Litigants, contracting parties, citizens subject to administrative action — these are the people actually living out the law. Professionals are, at most, intermediaries. If the mode of communicating a judgment prioritizes efficiency among professionals over comprehensibility for the parties, that is a defect in the legitimacy of law itself.
The Efficiency of Reduction, and the Asymmetry of Access
This is, in part, the fate of any legal system that functions by reducing complexity. As Niklas Luhmann argued, law functions as a predictable social system precisely because it reduces complex reality to a binary code of legal/illegal. This reduction is not simply unavoidable — it is functionally necessary.
The problem lies elsewhere: who possesses, and who lacks, the shared context needed to complete that reduced description — the single compressed line of reasoning. The professional community shares that context, and so can decode the compression. The party concerned does not, and cannot. The result is that reduction produces efficiency for professionals while simultaneously producing inaccessibility for the parties. This may not be deliberate exclusion, but structurally it has the same effect.
An Asymmetry That Holds at Home, and Fails Abroad
This asymmetry has held, as long as it stayed within Japan’s borders. As long as the professional community remained homogeneous, sharing an accumulated body of precedent and a common interpretive style, compressed reasoning could pass as “efficient.”
But take this style into the international arena — arbitration, investment disputes, treaty negotiation, integrative bargaining — and the moment it arrives, it stops working.
The reason is straightforward. An international tribunal or a foreign counterpart does not share the tacit premises that Japan’s professional community has built up over decades. The other side comes from a different country, a different legal culture; they know neither the lineage of Japanese precedent nor its conventions for reading a statute. So when one side states only a conclusion, briefly, there is no reason to expect the other side will fill in the reasoning behind it on its own.
There is an international rule governing how treaties are to be interpreted: the Vienna Convention on the Law of Treaties. Concluded in 1969, it sets out, in effect, a shared rulebook for how states should read the treaties they conclude. Article 31 requires that a treaty be interpreted not merely by its wording but in light of its object and purpose as a whole — what it was made for, what the parties intended by it. In other words, the international arena has, from the outset, built in a rule requiring a reading of the whole (purpose, background, intent) rather than a mechanical application of the parts (the text alone).
Judgments and arbitral awards in the Anglo-American tradition operate on the same premise. It is standard practice to set out, in careful and often lengthy reasoning, the path by which a conclusion was reached — why one fact was weighed heavily, why a given argument was rejected.
There is also a cultural difference in how opinions themselves are disclosed. Japan’s lower courts — district and high courts — issue a single, consolidated judgment, as though the court were a monolithic body that had arrived at one correct answer. Anglo-American courts, by contrast, allow individual judges to write long, separately reasoned opinions under their own names — concurring where they agree with the outcome but not the reasoning, dissenting where they disagree outright. Which judge thought what, and why, is laid bare. This contrast — between “writing as norm” and “writing as narrative,” and which of the two the Japanese Supreme Court itself has chosen at different moments — is examined at length in a companion piece, “Who Is a Supreme Court Ruling Written For? — Judicial Narrative Strategy, Japan and the United States Compared,” through a reading of the Sunagawa ruling, the eugenics-protection-law state redress case, and the U.S. Supreme Court’s decision in Trump v. Barbara. The argument there is that Japanese courts are not incapable of narrative; rather, they hold that capacity in reserve for extraordinary occasions — a change of precedent, a grave and sustained human-rights violation. In the context of this piece, that reserve is itself one expression of the very asymmetry under discussion here: efficient for the professional community, invisible to the party concerned.
Bring the style that has served at home — state the conclusion briefly, leave the reasoning behind it to professional tacit knowledge — into such a setting, and what happens? The other side has no shared knowledge to fill in that brevity. So it reads as “thin argument,” as “a conclusion without the reasoning spelled out.” What looks, from the Japanese side, like a conclusion arrived at through careful thought, leaves no visible trace of that thought for the other side to see.
In other words: the “efficiency for professionals” that has functioned only domestically comes back, in the international arena, as a cost borne by professionals themselves. Efficiency within a closed system reappears, in an open one, as a failure of accountability.
Conclusion: From a Closed Code to an Open Conversation
This is not merely academic idealism. In 2010, the U.S. Congress passed the Plain Writing Act, legally requiring federal agencies to write public documents and procedural guidance in language the intended reader can actually understand. The effort to return the language of law and administration from professionals to citizens is already more than a principle — it is running as concrete policy.
Returning to Garner’s critique, the conclusion is simple but weighty: legal documents ought to be written in language the people who actually use them can understand. This is not a matter of stylistic simplification alone. It is a question that goes to the root of law’s legitimacy — whether judicial reasoning and legal judgment should remain an efficient code compressed by professional tacit knowledge, or whether it should be opened into a form the parties and the public can understand and verify.
Should law remain something only professionals can decode, like an oracle? Or should it be remade into a platform on which the reasoning behind a judgment is spoken aloud — one where the people whose lives are shaped by that reasoning, and society as a whole, can examine it and respond? What the Nara case exposes is not only a gap in institutional protection against bullying. It is another kind of absence: the possibility that the judgment itself — the very form by which the most consequential legal decisions are communicated — has, in effect, said nothing at all to the party whose life it has just decided. Whether to leave that code closed, or to remake it into an open conversation, remains, for now, a choice still in our hands.