Appealing a Civil Judgment or Seeking a Retrial in Japan: What are the Grounds and Key Principles?

In Japanese civil litigation, a court's judgment does not necessarily mark the absolute end of a dispute. The legal system provides mechanisms for parties who believe a judgment is erroneous or unjust to seek further review or, in extraordinary circumstances, to challenge a judgment that has already become final and binding. These avenues are primarily appeals (jōso - 上訴), which are ordinary means of review by a higher court, and retrial (saishin - 再審), which is an extraordinary remedy used to attack a final judgment due to certain grave defects. Understanding the key principles governing these procedures, such as the "interest to appeal," the "prohibition of reformatio in peius," and the strict grounds for retrial, is essential for comprehending the full lifecycle of civil dispute resolution in Japan.

The Japanese Appellate System: An Overview

Japan employs a three-tiered court system for most civil matters, typically involving District Courts (or Summary Courts for smaller claims) as courts of first instance, High Courts as intermediate appellate courts, and the Supreme Court as the court of last resort.

There are principally two types of appeals against a judgment on the merits:

1. Kōso Appeal (控訴): This is an appeal from a judgment of a District Court or Summary Court to the competent High Court. A kōso appeal generally allows for a full review of the case, meaning the High Court can re-examine both questions of fact and questions of law. It is, in effect, a continuation of the trial at a higher level.
2. Jōkoku Appeal (上告): This is an appeal to the Supreme Court, typically from a judgment of a High Court. Unlike a kōso appeal, a jōkoku appeal is primarily limited to reviewing alleged errors of law, particularly violations of the Constitution or grave misinterpretations of other laws that clearly affect the judgment. The Supreme Court does not generally re-examine findings of fact made by the lower courts. (There is also a system of petitions for acceptance of a jōkoku appeal for cases that involve important questions of law but might not meet the strict criteria for a direct jōkoku appeal).

This article will focus on the general principles applicable to appeals, particularly those relevant to the kōso appeal, and the distinct remedy of retrial.

Interest to Appeal (Jōso no Rieki - 上訴の利益)

Not every party to a lawsuit can appeal a judgment. A fundamental prerequisite for lodging a valid appeal is the existence of an "interest to appeal" (jōso no rieki). This concept essentially means that the party seeking to appeal must have been aggrieved by the judgment of the lower court; they must have suffered some legal disadvantage as a result of that judgment.

• Core Concept: A party generally has an interest to appeal if the judgment rendered is less favorable to them than the outcome they had sought in their pleadings. If a party received everything they asked for (a complete victory), they typically have no grievance and thus no interest to appeal that favorable judgment. Conversely, a party who lost, either in whole or in part, is considered aggrieved and possesses the requisite interest.
• The "Formal Grievance" Theory (Keishiki-teki Fufuku Setsu - 形式的不服説): This has long been the traditional and dominant approach for determining the interest to appeal. It involves a relatively straightforward comparison:
  • The court compares what the party formally requested in their prayer for relief (in their complaint, if a plaintiff, or in their defense, if seeking dismissal as a defendant) with what the judgment actually granted or denied them.
  • If the judgment grants the party less than what they formally requested, they are deemed to have a "formal grievance" and thus an interest to appeal the unfavorable portion.
  • For example (Case in Chapter 6-25 of the reference material): Plaintiff X sues Defendant Y for ¥5 million.
    • If the court awards X the full ¥5 million (as in 【例1判決】), X has no formal grievance and cannot appeal. Defendant Y, who sought dismissal of the claim, is aggrieved by the ¥5 million award and can appeal.
    • If the court awards X only ¥3 million and dismisses the claim for the remaining ¥2 million (as in 【例2判決】), X is aggrieved with respect to the dismissed ¥2 million portion and can appeal that part. Y is aggrieved with respect to the ¥3 million awarded to X and can appeal that part.
• The "Substantive Grievance" / "New Substantive Grievance" Theory (Shin Jittai-teki Fufuku Setsu - 新実体的不服説): This alternative theoretical approach focuses less on the formal discrepancy between the request and the award, and more on whether the judgment, if it were to become final, would have adverse substantive legal effects (particularly res judicata or executory force) on the party. While this often leads to the same practical outcomes as the formal grievance theory, it can provide a more robust explanation for allowing appeals in "exceptional" situations where a party might have formally "won" but still faces some latent legal prejudice from the judgment.
• "Exceptional Grievance" (Reigai-teki Fufuku - 例外的不服): Even proponents of the formal grievance theory acknowledge that there can be exceptional circumstances where a party, despite having received a judgment that formally aligns with their prayer for relief, might still be considered aggrieved and allowed to appeal. These situations often involve a concern that the judgment, despite its favorable main text, carries some hidden disadvantage or fails to provide complete relief.
  • One classic example involves a defendant who successfully obtains a dismissal of the plaintiff's claim, but the dismissal is based on the court upholding the defendant's set-off defense. While the defendant "won" (the plaintiff's claim was dismissed), the successful set-off means the defendant's own counterclaim used for the set-off has been extinguished, and this finding (regarding the counterclaim) carries res judicata effect under CCP Article 114(2). The defendant might have preferred a dismissal on the grounds that the plaintiff's claim was invalid from the outset (which would not have sacrificed their counterclaim). In such a case, the defendant may be found to have an interest to appeal to seek a dismissal on these more favorable grounds, even though the main text of the judgment was a dismissal.
  • Another complex area, touched upon in the reference material (Chapter 6-25, Case), involves explicit partial claims. If a plaintiff sues for only part of a larger known claim and wins that part, they formally have no grievance. However, if there's a risk that the rules surrounding partial claims might (e.g., due to an insufficiently clear "explicit partial claim" declaration) lead to the preclusion of a subsequent suit for the remainder of the claim, some theories argue the plaintiff might have an interest to appeal the "favorable" judgment to seek clarification or to amend the claim at the appellate stage (if procedurally permissible) to include the full amount and avoid such preclusion. However, other formal grievance theorists are more restrictive, arguing that if the plaintiff had the opportunity to claim the full amount at first instance and failed to do so, they lack the interest to appeal a judgment that grants exactly what they did claim.

The existence of an "interest to appeal" is a fundamental prerequisite. If an appeal is lodged by a party found to lack such an interest, the appellate court will dismiss the appeal as procedurally improper without examining its merits.

Prohibition of Reformatio in Peius (Disadvantageous Alteration) (不利益変更禁止の原則 - Furieki Henkō Kinshi no Gensoku)

A crucial principle governing appellate review in Japan is the prohibition of reformatio in peius, codified in CCP Article 304. This rule states that the appellate court cannot alter the original judgment to the disadvantage of the appellant, unless the appellee (the party who did not appeal, or who won in part) has also filed their own appeal (kōso) or a cross-appeal (futai kōso - 附帯控訴, CCP Art. 293).

• Rationale: This principle serves to protect the appellant. It ensures that a party who exercises their right to appeal will not, as a result of their own appeal alone, be placed in a worse position than they were under the original judgment. Without this protection, potential appellants might be deterred from seeking appellate review for fear that the appellate court might not only reject their arguments but also uncover errors that lead to an even less favorable outcome for them. The rule thus encourages the use of the appellate process by providing a "safety net" for the appellant.
• Scope of "Disadvantage": Whether an alteration is "to the disadvantage" of the appellant is determined by comparing the potential appellate judgment with the original judgment from the appellant's perspective.
• Interaction with Appellee's Appeal or Cross-Appeal: If the appellee also challenges the first-instance judgment by filing their own appeal (if they also partially lost) or a cross-appeal (which can be filed even if their time for a direct appeal has passed, in response to the appellant's appeal), then the aspects of the judgment challenged by both sides are open for review. In such cases, the appellate court can modify the judgment in a way that might be disadvantageous to the original appellant compared to the first-instance judgment, but this modification would be based on the merits of the appellee's appeal or cross-appeal.
• Complexities Illustrated by Set-Off Defenses: The application of this principle can become quite intricate, especially in cases involving set-off defenses, as illustrated by the scenarios in Chapter 6-26 of the reference material.
  • Scenario: Plaintiff X sues Defendant Y for ¥10 million. Y raises a set-off defense using a ¥4 million counterclaim against X. The first-instance court finds X's ¥10 million claim valid and Y's ¥4 million counterclaim also valid. It therefore orders Y to pay X ¥6 million (¥10m - ¥4m). Only X appeals, arguing that Y's ¥4 million counterclaim was invalid and seeking the full ¥10 million. Y does not file an appeal or a cross-appeal.
  • Issue 1 (from Setsumon 1): Suppose Y, after the first-instance judgment, voluntarily pays X the awarded ¥6 million. In X's appeal, Y now asserts this payment. The High Court might agree that, due to this payment, X's remaining entitlement is ¥0 (assuming the High Court still finds the original claim was ¥10m and the set-off was ¥4m, leaving ¥6m, which has now been paid). However, because X is the sole appellant and Y has not cross-appealed to have the original ¥6m award reduced, the High Court cannot alter the judgment to X's further disadvantage. X appealed seeking more than ¥6 million. If the High Court finds X is not entitled to more than ¥6 million (because the original set-off was valid and the balance has been paid), it will simply dismiss X's appeal. The practical result is that X still effectively "gets" the ¥6 million. For Y to obtain a judgment reflecting the post-judgment payment (i.e., reducing Y's liability from ¥6 million to ¥0), Y would have needed to file a cross-appeal.
  • Issue 2 (from Setsumon 2): Again, only X appeals the ¥6 million award. However, the High Court, upon re-examining the case, comes to the preliminary conclusion that X's original ¥10 million claim was entirely invalid from the start, AND that Y's ¥4 million counterclaim (used for set-off) was also invalid. What judgment should the High Court render?
    According to the prevailing view and a Supreme Court decision of September 4, 1986 (Saibanshu Minji No. 148, p. 417), the High Court should still simply dismiss X's appeal. X appealed because X was dissatisfied with only getting ¥6 million instead of ¥10 million. The High Court's finding that X's original claim was entirely unfounded means X is certainly not entitled to more than ¥6 million (in fact, on the High Court's substantive view, X is entitled to ¥0). However, because Y did not appeal or cross-appeal to challenge the original ¥6 million award against them, the High Court is bound by the prohibition of reformatio in peius and cannot change the first-instance judgment to X's further disadvantage (i.e., it cannot reduce the ¥6 million award to ¥0, even if it believes ¥0 is the correct substantive outcome for X's original claim). The ¥6 million award in X's favor from the first instance would effectively stand because Y did not challenge it. This result—where a party benefits from an unappealed portion of a judgment even when an appellate court finds their underlying claim wholly without merit—is a direct consequence of the furieki henkō kinshi principle. (An alternative academic view argues that if X's claim is entirely unfounded, the appeal should lead to a dismissal of X's entire claim, but this is not the dominant judicial approach).
    The reference material notes that in such complex situations, the court's power to clarify (shakumei-ken) becomes important. If the High Court forms a preliminary view that X's entire claim is unfounded, it might subtly indicate this to Y, thereby prompting Y to consider filing a cross-appeal. If Y then files a cross-appeal challenging the original ¥6 million award, the High Court would then be free to render a judgment dismissing X's claim in its entirety, aligning the final outcome with its substantive findings.

Retrial (Saishin - 再審) (CCP Articles 338 et seq.)

Retrial is an extraordinary remedy distinct from ordinary appeals. It is a new legal proceeding initiated to seek the setting aside of a judgment that has already become final and binding and is no longer subject to ordinary appeal. Its purpose is to provide a mechanism for correcting grave errors or injustices that undermine the very foundation of a concluded judgment, thereby balancing the strong public interest in the finality of judgments (res judicata) with the imperative of achieving substantive justice in exceptional cases.

• Strictly Enumerated Grounds (CCP Art. 338(1)): A retrial action is permissible only for specific grounds exhaustively listed in the Code. These grounds generally fall into categories reflecting either:
  1. Grave Procedural Irregularities that Fundamentally Impaired a Fair Hearing:
     • Improper constitution of the court that rendered the judgment (item 1).
     • Participation of a judge who was legally disqualified from hearing the case (item 2).
     • A significant defect in legal representation or agency, such as a party being represented by someone who lacked the proper authority (item 3). The reference material's Case 1 in Chapter 6-27 involves a situation where service of process on the defendant was made by delivering documents to his 7-year-old child. If this service is deemed invalid, it could mean the defendant was never properly brought before the court and was effectively unrepresented or denied an opportunity to participate. A Supreme Court decision of September 10, 1992 (Minshū Vol. 46, No. 6, p. 553) allowed a retrial by analogy to Article 338(1)(iii) in a case involving such fundamentally defective service leading to a party's non-participation.
     • The judgment was rendered in violation of rules concerning exclusive jurisdiction (item 4, part 1).
  2. Tainted Evidence or Criminal Interference with the Judicial Process:
     • A party was induced to make an admission, or was prevented from presenting a crucial means of allegation or defense, by a criminally punishable act committed by another person (item 5). The reference material's Case 2 in Chapter 6-27, where a plaintiff alleged that the defendant's employee provided false information to the court about the plaintiff's address, leading to improper service by mail and a default judgment, touches upon this ground, particularly if the employee's act constituted a punishable offense that obstructed the plaintiff's ability to defend.
     • A document that was used as crucial evidence in the judgment was proven to be forged or altered (item 6).
     • The testimony of a witness, expert, or interpreter, or the sworn statement of a party or their statutory agent, upon which the judgment was based, has been proven to be false (perjury) (item 7).
     • A civil or criminal judgment, or an administrative disposition, that formed the basis of the original judgment has subsequently been altered by a final and binding decision (item 8).
  3. Other Specific Grounds:
     • The judgment omitted a decision on a crucial point that was part of the claim and should have been decided (item 9).
     • The judgment contradicts a prior final and binding judgment rendered on the same claim between the same parties (item 10).
• Requirement of Newness for Certain Grounds: For several grounds related to tainted evidence or false statements (specifically items 5 through 7 above), there's an additional prerequisite: a criminal conviction or a non-penal fine for the underlying wrongful act (e.g., perjury, forgery) must generally have become final and binding, or it must be impossible to obtain such a conviction for reasons other than a lack of evidence (CCP Art. 338(2)). This often presents a very high evidentiary bar for seeking retrial on these grounds.
• Strict Time Limits for Filing for Retrial (CCP Art. 342): An action for retrial is subject to strict time limitations. Generally, it must be filed within an inextensible period of 30 days from the day on which the party became aware of the ground for retrial. Furthermore, there is an absolute time limit: a retrial action generally cannot be filed if five years have elapsed since the original judgment became final and binding. There are some exceptions to this five-year limit, for example, if the ground for retrial only came into existence or became known to the party after the judgment had become final for a considerable time. These stringent time limits underscore the exceptional nature of retrial as a remedy that disturbs the finality of judgments.
• The "Supplementary Nature" of Retrial (Hojūsei - 補充性) (CCP Art. 338(1) proviso): A party cannot seek retrial on a ground that they either asserted in a prior ordinary appeal, or could have asserted in such an appeal but failed to do so due to their own negligence. Retrial is a remedy of last resort and is not available if the alleged defect could have been addressed through the normal appellate process.
  However, as discussed in the reference material's Case 1 scenario (defective service of the complaint, followed by service of the default judgment on the defendant's wife who concealed it), if the party was actually unaware of the ground for retrial (e.g., the defective service and the very existence of the judgment) during the period when an ordinary appeal could have been lodged (even if an appeal with a request for condonation of delay under CCP Art. 97 might have been theoretically possible upon later discovery), the supplementary nature rule may not bar a subsequent action for retrial. The Supreme Court decision of September 10, 1992, allowed retrial in such circumstances where the party genuinely had no opportunity to raise the defect in an appeal because they were unaware of the proceedings or the judgment itself due to no fault of their own.

Relationship Between Retrial and Other Potential Remedies

The reference material's Case 2 also touches upon whether a party who has suffered loss due to a judgment allegedly obtained by fraudulent or other unlawful means can pursue a separate action for damages in tort against the wrongful party, instead of (or perhaps in addition to) seeking a retrial of the original judgment.
A Supreme Court decision of July 8, 1969 (Minshū Vol. 23, No. 8, p. 1407) indicated that where a judgment was obtained through improper means that effectively prevented the other party from participating in the proceedings or presenting their defense, the aggrieved party might be able to sue for damages in tort. This was permitted even if a retrial might also be a theoretical option. This raises complex questions about potentially undermining the res judicata of the original judgment through a collateral tort action. Courts in such situations attempt to strike a balance between upholding the general finality of judgments and providing a remedy against egregious misconduct that taints the process of obtaining that judgment. The tort claim focuses on compensating for the damage caused by the wrongful act in procuring the judgment, while the retrial action aims at directly correcting or setting aside the flawed judgment itself.

Conclusion

The Japanese civil justice system provides structured avenues for challenging court judgments, but these are carefully designed to balance the fundamental need for error correction and substantive justice with the equally important imperative of ensuring the finality and stability of legal determinations. Ordinary appeals, such as the kōso appeal to a High Court, allow for a review of alleged errors committed by the lower court, and their conduct is governed by key principles including the requirement of an "interest to appeal" and the "prohibition of reformatio in peius." Retrial (saishin), on the other hand, is an extraordinary and highly circumscribed remedy. It is reserved for addressing very specific, grave defects that are considered to undermine the fundamental fairness or integrity of a judgment that has already become final and binding, and it is subject to strict substantive grounds and time limitations. These distinct mechanisms, operating at different stages and under different conditions, collectively reflect the legal system's commitment to providing both conclusive dispute resolution and avenues for redress against significant judicial or procedural failings.