Evidence in Japanese Civil Litigation: How It's Presented, Evaluated, and Reflected in Judgments – A Guide for U.S. Litigants

Evidence forms the backbone of any legal dispute, and its treatment within a judicial system is a critical factor for litigants. For U.S. parties involved in Japanese civil litigation, understanding how evidence is presented to the court, how judges evaluate it, and how these considerations are ultimately reflected in the written judgment (判決 - hanketsu) is paramount. While the quest for factual truth is universal, the methodologies and articulations in Japanese judgments have distinct characteristics rooted in Japan's civil law tradition.

This article explores the lifecycle of evidence as it moves through Japanese civil proceedings and crystallizes within the court's judgment, primarily focusing on how such evidence is discussed in the "Reasons" (理由 - riyū) section, which provides the court's justification for its findings.

General Principles of Evidence in Japanese Civil Litigation

Several core principles underpin the handling of evidence in Japan:

• Party Presentation Principle (当事者主義 - tōjisha shugi): In line with adversarial systems, the primary responsibility for gathering and submitting evidence rests with the litigating parties. The court generally makes its decision based on the evidence and arguments presented by the plaintiff and defendant.
• Free Evaluation of Evidence (自由心証主義 - jiyū shinshō shugi): This is a fundamental tenet. Japanese judges are not bound by rigid, formalistic rules on the admissibility or weight of specific types of evidence (with some exceptions for illegally obtained evidence). Instead, they are tasked with evaluating all admissible evidence rationally, based on their legal training, experience, logic, and the entire context of the proceedings to form a "free conviction" as to the facts.
• Limited Pre-Trial Discovery: Unlike the extensive pre-trial discovery common in the United States (e.g., depositions, interrogatories, broad document requests), Japan has more limited mechanisms for compelled evidence gathering before the main oral argument stages. Evidence is often developed and presented incrementally through submissions of briefs and exhibits during the course of proceedings, with a focus on documents and witness examination in court.
• Burden of Proof (立証責任 - risshō sekinin): The party asserting a particular fact generally bears the burden of proving it. The judgment will ultimately reflect whether the court found that this burden was met for each essential contested fact. The standard is typically a balance of probabilities, akin to the "preponderance of the evidence" standard in the U.S.

Types of Evidence and Their Reflection in Judgments

The primary section of a Japanese judgment where the court's engagement with evidence is detailed is the "Reasons" (理由 - riyū) section. This is where the court makes its findings of fact (事実の確定 - jijitsu no kakutei). While the "Facts" (事実 - jijitsu) section outlines the parties' allegations and thus indirectly refers to the evidence they rely on, it's in the "Reasons" that the court's assessment and reliance on specific pieces of evidence become explicit.

1. Documentary Evidence (書証 - shoshō)

Documents often play a central role in Japanese civil cases.

• Referencing in Judgments: Documentary evidence is meticulously cataloged and referred to by exhibit numbers (e.g., 甲第1号証 - Kō dai-ichi-gō shō for Plaintiff's Exhibit No. 1; 乙第1号証 - Otsu dai-ichi-gō shō for Defendant's Exhibit No. 1). The judgment will cite these exhibits when discussing the facts derived from them but will not typically reproduce the documents themselves.
• Authenticity (成立の真正 - seiritsu no shinsei): A document's content cannot be considered as evidence unless its authenticity is established. The judgment will often address this:
  • Undisputed Authenticity: Phrased as 「成立に争いのない甲第1号証」 ("Exhibit Ko-1, the authenticity of which is not disputed").
  • Proven Authenticity: If authenticity was disputed, the judgment might explain how it was proven, for example, through witness testimony confirming a signature, or by relying on legal presumptions.
    • Official Documents (公文書 - kōbunsho): Documents appearing to have been prepared by a public official in the course of their duties are presumed to be authentic official documents.
    • Private Documents (私文書 - shibunsho): A private document is presumed to be authentically made if it bears the signature or seal (印影 - in'ei) of the alleged maker (or their agent), and that signature or seal is proven to be genuine. The party disputing authenticity then has the burden to rebut this presumption. Given the traditional importance of seals (印鑑 - inkan) in Japanese society for executing documents, judgments may contain detailed discussions on the evidence proving the genuineness of a seal impression.
• Probative Value: Once authenticated, the court assesses the document's evidentiary weight. "Dispositive documents" (処分証書 - shobun shōsho), such as contracts or deeds created to establish or prove a legal act, are generally given high probative value regarding the occurrence of that act.
• Copies (写し - utsushi) vs. Originals (原本 - genpon): Court rules generally require the submission of originals, true copies, or certified copies. If a copy is submitted, especially if the original is unavailable, the court might consider arguments related to its accuracy and may note its reliance on a copy if authenticity and correspondence to the original are established or undisputed.

2. Witness Testimony (人証 - ninshō)

Testimony from individuals provides another crucial source of evidence.

• Types of Testifying Individuals: This category includes:
  • Witnesses (証人 - shōnin): Third-party individuals with knowledge relevant to the case.
  • Parties Themselves (当事者本人 - tōjisha honnin): Plaintiffs or defendants testifying about their own knowledge.
  • Representatives of Legal Entities (代表者 - daihyōsha): Such as the representative director of a company.
• Referencing in Judgments: The judgment will refer to testimony by identifying the individual, e.g., 「証人Aの証言によれば…」 ("According to the testimony of Witness A..."). If a witness was examined multiple times, this may be noted, such as 「証人A（第1回、第2回）」 ("Witness A (first examination, second examination)"). Testimony given before a commissioned judge is still referred to as that witness's testimony, not the record itself.
• Evaluation of Credibility (信用性 - shin'yōsei): This is a critical judicial function. The judge, having directly observed the testimony (in most instances), assesses credibility based on various factors:
  • The witness's opportunity and capacity to perceive the events testified to.
  • The clarity, consistency, and inherent plausibility of the testimony.
  • The witness's demeanor.
  • Any interest or bias the witness may have in the outcome of the case.
  • The witness's relationship to the parties.
  • The witness's memory.
    The judgment may explicitly state reasons for finding testimony credible or not, especially if it's pivotal or conflicts with other evidence. For instance, it might say, "Witness A's testimony aligns with the undisputed documentary evidence and was delivered in a forthright manner, hence it is deemed credible," or conversely, "Defendant B's testimony on this crucial point was vague and contradicted by their earlier statements, and therefore lacks credibility."
• Hearsay (伝聞証言 - denbun shōgen): While the strict exclusionary rules for hearsay found in U.S. criminal law do not apply in the same way in Japanese civil cases, the indirect nature of hearsay testimony will naturally affect its weight in the judge's free evaluation.
• Written Statements in Lieu of Oral Examination (書面尋問 - shomen jinmon): In some circumstances, a witness may provide a written statement answering questions. This is typically treated more like documentary evidence in terms of how it's presented and evaluated.

3. Expert Opinions (鑑定 - kantei)

When specialized knowledge is required to understand an issue, the court may rely on expert opinions.

• Source: Experts can be appointed by the court or, in some cases, agreed upon by the parties. Their findings are usually submitted in a written report (鑑定書 - kanteisho).
• Referencing in Judgments: 「鑑定の結果によれば…」 ("According to the results of the expert opinion...") or similar phrasing is used.
• Evaluation: Judges are not bound by expert opinions; they are one piece of evidence to be considered under the principle of free evaluation. The judgment may discuss the expert’s qualifications, methodology, and the reasoning behind their opinion, explaining why the court found it persuasive or unpersuasive on particular points.

4. Inspections (検証 - kenshō)

The court may conduct a physical inspection of a place (e.g., a property in dispute) or an object.

• Referencing in Judgments: 「検証の結果によれば…」 ("According to the results of the inspection..."). The observations made during the inspection are recorded in an inspection record (検証調書 - kenshō chōsho), which becomes part of the court file.

5. Commissioned Examinations/Inquiries (調査嘱託 / 鑑定嘱託 - chōsa shokutaku / kantei shokutaku)

The court can request information or reports from public agencies, private organizations, or other third parties who possess specialized knowledge or relevant data.

• Referencing in Judgments: 「調査嘱託の結果によれば…」 ("According to the results of the commissioned inquiry...") or 「鑑定嘱託の結果によれば…」 ("According to the results of the commissioned expert report..."). The responses received become evidence in the case.

How Evidence (or Its Absence) Shapes the "Reasons" Section

The "Reasons" (理由 - riyū) section of the judgment meticulously explains how the court arrived at its factual findings based on the evidence.

• Affirmative Findings (Fact Proven):
  When the court determines that a disputed fact has been proven by the party bearing the burden of proof, the judgment will typically:
  1. Clearly state the fact that has been found.
  2. Identify the specific pieces of evidence that support this finding. For example, "Based on the contents of Exhibit Ko-1 (contract document) and the consistent testimony of Witness A and Plaintiff herself, the court finds that an agreement was reached on regarding ."
  3. If there was conflicting evidence submitted by the opposing party, the judgment should ideally explain why that evidence was deemed less credible or insufficient to overturn the finding. For instance, "While Defendant testified to the contrary, this testimony lacks corroboration and is inconsistent with the contemporaneous written records in Exhibit Ko-1; therefore, the court cannot adopt Defendant’s testimony on this point".
• Negative Findings (Fact Not Proven):
  When the court concludes that an alleged fact has not been proven by the party who bore the burden of proof, the judgment will state this clearly.
  1. The phrasing often used is 「…を認めるに足りる証拠はない。」 (...o mitomeru ni tariru shōko wa nai. – "There is insufficient evidence to find/recognize...") or 「…の事実は認められない。」 (...no jijitsu wa mitomerarenai. – "The fact of... cannot be found/recognized.").
  2. The court may discuss the evidence proffered by the proponent of the fact and explain why it was deemed insufficient, unreliable, or unpersuasive.
  3. It's important to note that this is generally a finding that the burden of proof was not met, rather than a positive finding of the non-existence of the fact. However, in some situations, if there is strong evidence to the contrary, the court might go further and find the opposite fact to be true. For example, "There is insufficient evidence to support Plaintiff's claim that the payment was a loan; on the contrary, the testimony of Witness C and Exhibit Otsu-2 (gift acknowledgment) indicate that the payment was a gift."
• The "Entire Tenor of Oral Argument" (弁論の全趣旨 - benron no zen shushi):
  This distinctively Japanese concept allows the court to consider the overall impression gained from the entire course of the oral argument proceedings. This can include the parties' conduct, the manner of their presentations, their responses to questioning, the timing of submissions, and other observations made by the judge.
  It is usually cited as a supplementary factor in conjunction with specific evidence when the court makes its overall assessment of the facts, e.g., 「甲第1号証、証人Aの証言及び弁論の全趣旨を総合すれば…」 ("Taking into comprehensive consideration Exhibit Ko-1, the testimony of Witness A, and the entire tenor of oral argument..."). It rarely forms the sole basis for determining a crucial disputed fact.

Evidentiary Citations and Exclusions in Judgments

The way evidence is cited or discussed provides insight into the court's reasoning.

• Specificity of Citations: Judgments are expected to cite specific evidence supporting findings on disputed facts, rather than making broad, unsupported assertions or vague references like "based on all the evidence".
• Order of Citing Evidence: There is a general custom to cite documentary evidence first, followed by witness testimony (witnesses, then parties/representatives), then expert opinions, inspections, and commissioned inquiries, although the court may also list them in order of importance to the specific finding.
• Reasons for Not Relying On or Excluding Evidence:
  • A court is not obligated to explain in the judgment why every single piece of evidence submitted was not relied upon or was given little weight.
  • However, for significant evidence, particularly if it directly contradicts the court's ultimate finding or was a central point of contention, it is good judicial practice (and sometimes necessary to avoid the judgment being criticized for inadequate reasoning) to explain why it was not adopted. This might involve explicitly stating that a witness was not credible, a document lacked authenticity or relevance, or an expert opinion was unpersuasive.
  • If a document's authenticity is not established, that is a clear ground for not relying on its contents as evidence.

Practical Implications for U.S. Litigants

For U.S. litigants, several aspects of Japanese evidentiary practice as reflected in judgments are noteworthy:

• Emphasis on Documentary Proof: Strong, authenticated documentary evidence often carries significant weight. The meticulous process surrounding document authenticity, including the role of seals, should be appreciated.
• Judicial Assessment of Credibility: Since there are no juries in civil cases, the judge is the sole arbiter of fact and credibility. The "Reasons" section offers a direct view into this assessment.
• The Narrative of Proof: The judgment effectively tells the story of how the court sifted through the presented evidence to arrive at its version of the facts. This narrative is crucial for understanding the basis of the outcome and for formulating any grounds for appeal.
• Impact of Limited Discovery: Because extensive U.S.-style pre-trial discovery is absent, the evidence that is formally submitted and tested during the main court proceedings (oral argument stages) takes on heightened importance. The judgment will focus on this body of evidence.

Conclusion

Evidence is the lifeblood of civil litigation in Japan, just as it is elsewhere. The written judgment, particularly its "Reasons" section, provides a detailed account of how the Japanese court engaged with the evidence presented by the parties. It explains not only what facts the court found, but also how it arrived at those findings through the evaluation of documents, testimony, and other forms of proof under the guiding principle of free evaluation. For U.S. litigants, a careful and informed reading of these evidentiary discussions within a Japanese judgment is essential for a profound understanding of the case's resolution and the court's rationale, paving the way for more effective legal strategy in Japan.