Understanding the Three Pillars of the "Adversarial Principle" (弁論主義) in Japanese Civil Trials

In a previous overview, we introduced the "Principle of Party Presentation," or Benron-shugi (弁論主義), as a cornerstone of Japanese civil litigation, emphasizing the primary role of the litigating parties in shaping the factual and evidentiary landscape of their dispute. This principle, akin to the adversarial nature of common law systems, ensures party autonomy and judicial impartiality. However, to truly grasp its operational significance, it's essential to understand its three core propositions or "pillars" (often referred to as "theses" - テーゼ). These pillars dictate how facts are introduced, how undisputed facts are treated, and how evidence is presented, profoundly impacting case strategy and outcomes. This article delves into these three pillars in detail.

I. Revisiting the Principle of Party Presentation (Benron-shugi): Its Essence and Rationale

Before dissecting its pillars, let's briefly recap the essence of Benron-shugi. It mandates that (1) parties are responsible for alleging the facts supporting their claims/defenses, (2) parties must proffer evidence to prove contested facts, and (3) the court bases its judgment primarily on these party-submitted materials. This stems from respect for private autonomy in civil disputes, the desire to ensure procedural fairness by preventing judicial surprise (fuiuchi bōshi 不意打ち防止), and the need to maintain judicial neutrality. Crucially, Benron-shugi applies most rigorously to "principal facts" (shuyō jijitsu 主要事実)—those facts that directly establish or negate a legal right or effect under substantive law.

II. The First Pillar: The Imperative of Party Allegation (Burden of Allegation - 主張責任 Shuchō sekinin)

A. "No Judgment on Unalleged Facts": The Foundational Rule

The first, and arguably most fundamental, pillar of Benron-shugi is that the court cannot base its judgment on principal facts that have not been asserted (alleged) by either party. Even if evidence presented incidentally suggests the existence of a crucial fact, if neither the plaintiff nor the defendant has formally pleaded that fact as part of their claim or defense, the court is generally precluded from considering it as a basis for its decision.

• Implication: This places a significant burden on parties to be thorough and comprehensive in their pleadings (complaint - sojō 訴状, answer - tōbensho 答弁書, preparatory briefs - jumbi shomen 準備書面, etc.). Omitting a key principal fact necessary to establish a claim (e.g., failing to allege a specific term in a contract that was breached) can be fatal, even if the underlying reality supports that fact. The court will not, as a rule, "fill in the gaps" for a party's deficient allegations of principal facts.

B. Identifying and Pleading Principal Facts (Shuyō jijitsu)

1. What are Principal Facts? These are the ultimate facts that directly correspond to the elements of a legal rule (e.g., in a contract claim: formation of contract, terms, performance by plaintiff if a condition, breach by defendant, damages, causation). They are distinct from:
   • Indirect Facts (Kansetsu jijitsu 間接事実): Facts from which principal facts can be inferred (e.g., evidence of regular past payments might be an indirect fact supporting the existence of a loan agreement, which is a principal fact).
   • Auxiliary Facts (Hojo jijitsu 補助事実): Facts that affect the credibility or probative value of evidence (e.g., a witness's prior inconsistent statement).
     While parties will also argue about indirect and auxiliary facts, the strict rule of party allegation applies to principal facts.
2. Specificity in Pleadings: Japanese civil procedure generally requires a higher degree of specificity in pleading principal facts than, for example, the "notice pleading" standard found in U.S. federal courts. The allegations must be concrete enough for the opposing party to understand the precise factual basis of the claim or defense and to prepare a response. Vague or overly general allegations of principal facts may be insufficient.

C. The Principle of Commonality of Allegations (Shuchō kyōtsū no gensoku - 主張共通の原則)

This principle complements the first pillar. It means that a principal fact validly alleged by one party and appearing in the court record can be taken into consideration by the court, even if it benefits the opposing party who did not initially allege it. The court considers the entirety of the factual allegations properly before it, regardless of who introduced them.

D. Interplay with the Court's Power of Clarification (Shakumei-ken - 釈明権)

While parties bear the responsibility to allege facts, Article 149 of the Code of Civil Procedure grants the court a "power of clarification" (shakumei-ken). The judge can (and sometimes has a duty to) ask questions or encourage parties to clarify ambiguous statements, supplement incomplete allegations, or address inconsistencies.

• Purpose: This power is not to allow the judge to introduce new, unalleged principal facts, but to ensure that the parties' existing allegations are presented clearly and comprehensively, so that the case can be decided on a proper factual understanding. It helps prevent meritorious cases from failing due to easily correctable pleading errors.
• Example: If a plaintiff's claim for damages is unclear as to its calculation method, the judge might ask for clarification or supplementation.
• Limits: The exercise of shakumei-ken must not cross the line into the court effectively making a party's case for them or suggesting entirely new factual theories not contemplated by the parties. There is a long line of case law exploring the appropriate scope of this power, such as the Supreme Court judgment of May 26, 1970 (Minshu Vol. 24, No. 5, p. 413), which discussed the court's role in clarifying points necessary for legal assessment.

E. Practical Implications for Businesses

• Meticulous Pre-Filing Investigation: Thoroughly investigate and identify all principal facts necessary to support each element of your claim or defense before filing.
• Comprehensive Pleading: Ensure your complaint or answer clearly and specifically alleges all these principal facts. Do not assume the court will infer missing essential elements.
• Example (Contract Dispute): If suing for breach of a complex service agreement, don't just allege "breach"; allege the specific contractual obligations, how they were breached (specific acts or omissions by the defendant), when the breaches occurred, and how they caused the specific damages claimed.

III. The Second Pillar: The Binding Force of Judicial Admissions (自白の拘束力 - Jihaku no kōsoku-ryoku)

The second pillar concerns how facts that are not disputed between the parties are treated.

A. "Uncontested Facts Bind the Court": The Rule of Judicial Admission

A "judicial admission" (saiban-jō no jihaku 裁判上の自白) occurs when a party, during formal court proceedings, makes a clear statement that acknowledges the truth of a principal fact alleged by the opposing party, where that fact is disadvantageous to the admitting party.

• Binding Effect: Such a judicial admission is binding on both the party who made it and the court. The court cannot make a factual finding contrary to a valid judicial admission regarding a principal fact. The admitted fact is taken as true, and no further evidence is required to prove it. This promotes efficiency by narrowing the issues in dispute.

B. Strict Requirements for a Judicial Admission

For a statement to constitute a binding judicial admission, several conditions must be met:

1. Statement Made in Court Proceedings: The admission must be made during oral arguments (kōtō benron 口頭弁論) or formal preparatory proceedings (benron jumbi tetsuzuki 弁論準備手続), or in a brief submitted for these proceedings and clearly confirmed. Out-of-court admissions have evidentiary value but are not "judicial admissions" with this binding procedural effect.
2. Concerning a Principal Fact: The admission must relate to a shuyō jijitsu (principal fact). Admissions of indirect facts or auxiliary facts generally do not have the same binding effect on the court, though they influence the free evaluation of evidence.
3. Fact Alleged by the Opponent and Disadvantageous to the Admitter: The admitted fact must be one that the opposing party has alleged and that is unfavorable to the party making the admission.
4. Clear and Unequivocal: The statement must be a clear and unambiguous acknowledgment of the fact.
5. Made by a Party with Capacity or Their Authorized Representative: The admission must be made by a party with capacity to litigate or by their duly authorized legal counsel.

C. What Cannot Be Admitted (or Where Admission is Not Conclusive)

• Legal Conclusions: A party cannot make a binding admission on a point of law (e.g., "I admit I was negligent" – negligence is a legal conclusion, though the underlying facts leading to it can be admitted).
• Facts Contrary to Public Knowledge or Morality: Admissions of facts that are clearly contrary to notorious public knowledge or public order and morality are not binding.
• "Rights Admissions" (Kenri jihaku 権利自白): An admission regarding the existence or non-existence of a legal right itself (as opposed to the facts giving rise to it) is generally not considered binding on the court, as the determination of rights is the court's function based on the facts and law.

D. Restrictions on Withdrawing Judicial Admissions
Once a valid judicial admission is made, it is very difficult to withdraw. Withdrawal is generally permitted only under extremely limited circumstances, such as:

1. If the admission was made due to a mistake of fact (not law) and is contrary to the truth, and the mistake was not due to the gross negligence of the admitting party.
2. If the admission was induced by a criminal act of the opposing party (e.g., fraud or duress that meets criminal standards).
   The Supreme Court has been very strict on this (e.g., Supreme Court, March 10, 1967, Minshu Vol. 21, No. 2, p. 295). The policy is to ensure certainty and reliance on statements made in court.

E. Practical Implications for Businesses

• Extreme Caution with Admissions: Any statement made in pleadings or in court that could be construed as an admission of an unfavorable fact must be carefully considered and vetted by legal counsel.
• Strategic Use of Requests for Admission (though not a formal device like in the US): While Japan doesn't have formal "requests for admission" as a discovery tool, plaintiffs will frame their allegations to elicit responses that might constitute admissions.
• Precision in Responses: When responding to an opponent's allegations, deny unfavorable facts clearly if they are disputed. Avoid ambiguous language that could be interpreted as an admission.

IV. The Third Pillar: Party Responsibility for Proffering Evidence (Burden of Offering Evidence - 証拠提出責任 Shōko teishutsu sekinin)

The third pillar dictates that the parties, not the court, are primarily responsible for bringing forward the evidence necessary to prove their contested factual allegations.

A. "Parties Must Furnish Proof": The General Rule
If a principal fact alleged by one party is denied by the other, the party whose claim or defense depends on that fact must offer evidence to prove it. The court generally will not proactively search for or introduce evidence that the parties themselves have not proposed. This is a direct consequence of the adversarial nature of the proceedings.

B. Relationship with the Principle of Free Evaluation of Evidence (Jiyū shinshō-shugi)
This pillar works in conjunction with the Principle of Free Evaluation of Evidence (Art. 247 CCP). Parties offer evidence (Benron-shugi), and then the judge freely evaluates its probative value (Jiyū shinshō-shugi) to determine whether a fact has been proven to the requisite standard (typically "high degree of probability").

C. The Principle of Commonality of Evidence (Shōko kyōtsū no gensoku - 証拠共通の原則)
Evidence properly submitted into the court record by one party can be used by the court to make findings of fact, whether those findings are favorable to the party who submitted it or to the opposing party. The court is not limited to using evidence only for the party who introduced it.

D. Limited Role of Ex Officio Evidence Examination (Shokken shōko shirabe - 職権証拠調べ)
While the primary responsibility for offering evidence rests with the parties, the Code of Civil Procedure does allow for limited ex officio (by the court's own initiative) examination of evidence in certain circumstances. For example:

• The court can order an expert examination (kantei 鑑定) if it deems it necessary (Art. 218 CCP).
• The court may examine evidence concerning procedural requirements (e.g., jurisdiction, capacity).
• In matters deemed to involve significant public interest, the court might take a more active role.
  However, these are exceptions, and in typical commercial litigation, the expectation is firmly on the parties to present their own evidence.

E. Practical Implications for Businesses

• Proactive Evidence Gathering and Preservation: Businesses must have robust systems for identifying, gathering, and preserving relevant evidence (including electronic data) well in advance of and during litigation.
• Strategic Evidence Presentation: Decide which evidence is most persuasive and how to present it effectively (e.g., through clear documentary exhibits, well-prepared witness testimony).
• Consequences of Failure to Offer Evidence: If a party fails to offer sufficient evidence to support a contested key factual allegation for which they bear the burden of proof, that allegation will likely not be found true by the court.
• Document Production Orders: While parties must offer their own evidence, they can also seek court orders compelling the opposing party or third parties to produce specific, relevant documents they hold (as discussed in a separate article).

V. The Interplay and Balance: Benron-shugi in the Ecosystem of Japanese Civil Procedure

The three pillars of Benron-shugi do not operate in a vacuum. They interact with each other and with other fundamental principles of Japanese civil procedure:

• Interrelation of Pillars: The need to allege facts (Pillar 1) dictates what facts need to be proven by evidence (Pillar 3), and admissions (Pillar 2) can obviate the need for evidence on certain facts.
• Role of the Court's Power of Clarification (Shakumei-ken): This power acts as a crucial moderating influence, ensuring that the strict application of party responsibility does not lead to unjust outcomes due to easily remedied procedural missteps by the parties.
• Relationship with Party Disposition (Shobunken-shugi 処分権主義): While Benron-shugi governs the presentation of materials within a lawsuit, Shobunken-shugi gives parties control over the initiation, scope, and termination of the lawsuit itself.
• The Ultimate Goal: The entire system, including Benron-shugi and its modifying principles, aims to achieve substantive justice through a fair and efficient adversarial process, where parties have a full opportunity to present their case.

Conclusion

The three pillars of the Principle of Party Presentation—the responsibility to allege facts, the binding nature of judicial admissions, and the responsibility to proffer evidence—form the operational backbone of party-driven civil litigation in Japan. They place a significant onus on the litigants to meticulously prepare and actively present their cases. For businesses, a deep understanding of these principles and their practical implications is not merely beneficial but indispensable for effectively navigating the complexities of Japanese civil trials, protecting their interests, and maximizing their chances of a favorable outcome.