Partial Claims in Japan: Can You Sue for Only Part of a Debt, and What Happens to the Remainder?

Japanese Attorney at Law - Bengoshi L.L.

• 9 min read

When faced with a quantifiable monetary claim or a divisible obligation, a strategic question often arises for potential plaintiffs: is it necessary to sue for the entire amount at once, or can a claim be brought for only a portion, perhaps to test the legal waters, manage costs, or for other tactical reasons? In Japanese civil procedure, suing for only part of a larger claim is known as an "partial claim" (一部請求 - ichibu seikyū).

This article explores the permissibility of making partial claims in Japan, and crucially, examines the legal consequences for the un-sued remainder, particularly concerning the scope of res judicata (binding effect of judgment) and the tolling or renewal of statutes of limitations (prescription).

I. Understanding Partial Claims (Ichibu Seikyū) in Japan

A. What is a Partial Claim?

A partial claim refers to a lawsuit in which the plaintiff seeks to recover only a specified portion of a larger, known, and divisible monetary debt or other quantifiable obligation. For example, if a creditor is owed JPY 10 million, they might choose to file a lawsuit claiming only JPY 3 million as a partial payment.

B. Permissibility: An Extension of Party Disposition

As a general rule, partial claims are permissible in Japanese civil procedure. This stems from the Principle of Party Disposition (shobunken-shugi), a fundamental tenet which grants parties, particularly the plaintiff, control over the initiation and scope of their lawsuit. Since the plaintiff can decide what to claim, they can generally choose to claim only a part of what they believe they are owed.

However, this permissibility is not entirely absolute. In extremely rare circumstances, if the filing of a partial claim (or a series of them) is deemed to be a clear abuse of rights (権利の濫用 - kenri no ranyō) – for instance, if done purely for harassment or to vexatiously prolong a dispute with no legitimate purpose – a court might find it impermissible. But for legitimate strategic or practical reasons, partial claims are an accepted feature of the system.

C. The Crucial Distinction: Express vs. Implied/Unclear Partial Claims

For a partial claim strategy to be effective and predictable in its consequences, clarity is paramount:

  1. Express Partial Claim (Meiji-teki Ichibu Seikyū): This is where the plaintiff, in their complaint (訴状 - sojō), explicitly states that they are suing for only a part of a larger, identified claim and that they are reserving the right to sue for the remaining portion later. For example, "The plaintiff claims JPY 3,000,000 as a part of the total outstanding loan of JPY 10,000,000, and reserves the right to claim the remaining JPY 7,000,000." This clear expression of intent is vital for defining the scope of the current lawsuit and its effect on the remainder.
  2. Implied or Unclear Partial Claim: If a plaintiff sues for an amount that is less than the total apparent debt but fails to explicitly state that it is a partial claim with a reservation of the remainder, ambiguity arises. The court would likely seek clarification (under its shakumeiken, or right/duty to clarify) as to the plaintiff's true intent and the intended scope of the soshōbutsu (subject matter of litigation). Such ambiguity can lead to unintended consequences regarding res judicata or statutes of limitations.

Therefore, making an express partial claim with a clear reservation is the standard and highly recommended practice.

II. The Subject Matter of Litigation (Soshōbutsu) in Partial Claims

When a plaintiff makes an express partial claim, the soshōbutsu of that particular lawsuit is generally understood to be limited to the specific portion claimed. The court's adjudication will focus solely on the existence and validity of that partial amount. The un-sued remainder is not, at that point, before the court for determination.

III. Res Judicata (Kihanki-ryoku) and Partial Claims: What Happens to the Remainder?

One of the most critical questions for any litigant considering a partial claim is what effect a judgment on that partial claim will have on their ability to later sue for the remainder.

A. The General Rule for Express Partial Claims

The well-established general rule in Japan is that a final and binding judgment rendered on an expressly stated partial claim (where the remainder is reserved) does not have res judicata effect on the un-sued remainder of the claim.

  • This means that the plaintiff is generally free to file a subsequent lawsuit to recover the remaining portion of the debt or obligation. The earlier judgment only creates res judicata for the specific part that was litigated.
  • A foundational Supreme Court case affirming this is the judgment of August 10, 1962 (Second Petty Bench, Minshū Vol. 16, No. 8, Page 1720). This case established that if a plaintiff, when making a partial claim for a monetary debt, expressly reserves the right to claim the remainder, the res judicata effect of the judgment on the partial claim does not extend to the reserved remainder.

B. Importance of Clear Indication in the Complaint

To ensure this outcome and avoid any arguments that the first suit was intended to resolve the entire matter (despite claiming a lesser sum), it is imperative for the plaintiff to:

  1. Clearly state in the complaint that the amount claimed is only a part of a larger, identifiable total obligation.
  2. Explicitly reserve the right to claim the remaining balance in a separate action.

Without such clarity, there's a risk that a defendant might argue, or a court might infer (though less likely if a specific sum is claimed from a larger identifiable whole), that the initial suit was intended to be a full and final settlement of the entire underlying right, potentially leading to unintended preclusive effects.

C. Are There Exceptions Where Res Judicata Might Extend to the Remainder?

True exceptions where res judicata from an expressly and properly formulated partial claim bars a subsequent suit for the remainder are virtually non-existent under current Japanese law. The principle of party disposition allows the plaintiff to define the scope.

However, theoretical arguments could arise if the subsequent claim for the remainder, in very specific and unusual circumstances, were deemed to constitute an abuse of rights or to be profoundly contrary to the principles of good faith and procedural fairness (e.g., if the partial claim strategy was used in a demonstrably vexatious manner to harass the defendant with multiple suits on trivially small portions of an easily ascertainable whole). But these would be extreme and exceptional situations, not the standard rule.

IV. Statutes of Limitations (Prescription - Shōmetsu Jikō) and Partial Claims

Beyond res judicata, a crucial concern with partial claims is their effect on the statute of limitations (消滅時効 - shōmetsu jikō – or, under the amended Civil Code, the rules for "postponement of completion of prescription" and "renewal of prescription" (時効の完成猶予・更新 - jikō no kansei yūyo/kōshin)). Does filing a partial claim stop the clock for the entire underlying debt, or only for the portion claimed?

A. Traditional View: Interruption Limited to the Claimed Portion

For a long time, the prevailing judicial view, based on older Supreme Court precedents (e.g., Supreme Court, December 24, 1954, Second Petty Bench, Minshū Vol. 8, No. 12, Page 2281), was that the filing of an express partial claim generally interrupted (or postponed/renewed) the running of the statute of limitations only for the specific monetary amount claimed in that lawsuit. The prescription period for the un-sued remainder of the debt was considered to continue running independently. This created a significant risk for plaintiffs if the remainder was not sued upon before its own limitation period expired.

B. The Modern Shift: Supreme Court, July 7, 2017

A landmark decision by the Supreme Court on July 7, 2017 (Second Petty Bench, Minshū Vol. 71, No. 7, Page 971) introduced a significant and more nuanced approach to this issue.

  • Core Holding: While the Court reaffirmed the basic principle that an express partial claim, in itself, only has the effect of postponing/renewing prescription for the claimed portion, it carved out an important exception. The Court ruled that if the content of the complaint for the partial claim, or the plaintiff's conduct throughout the litigation of that partial claim, objectively and clearly manifests an intent to assert and seek satisfaction of the entire underlying divisible claim, then the filing of the partial claim can have the effect of postponing/renewing prescription for the entire claim (both the claimed part and the reserved remainder).
  • "Objective Manifestation of Intent": The key is whether the plaintiff, despite formally claiming only a part, has made it objectively clear through their pleadings and actions that they are asserting their right to the whole underlying debt or obligation. This requires more than just a cursory mention of a larger debt. Factors that might contribute to such a finding could include:
    • Explicitly detailing the total amount of the underlying debt in the complaint and how the partial claim relates to it.
    • Presenting evidence and arguments that go to the validity and existence of the entire debt, not just the partial sum.
    • Consistently maintaining a litigation posture that indicates an intention to eventually recover the full amount.
  • Implications: This ruling offers a pathway for plaintiffs to toll the statute of limitations for an entire claim through a carefully constructed partial claim. However, it also introduces a degree of uncertainty, as the assessment of whether the "intent to assert the entire claim" has been "objectively and clearly manifested" will depend on the specific facts and the court's interpretation. Failure to meet this standard means the traditional rule (interruption only for the claimed part) will apply.

V. Strategic Use and Considerations for Partial Claims

Filing a partial claim can be a deliberate strategic choice with potential benefits and drawbacks.

A. Potential Advantages

  1. Reduced Initial Court Filing Fees (Stamp Duty - 印紙代 inshi-dai): In Japan, court filing fees are calculated as a percentage of the amount claimed. Filing for a smaller, partial amount reduces the upfront litigation cost.
  2. "Test Case" or "Pilot" Litigation: If the legal basis of a claim is uncertain, or if crucial evidence is difficult to obtain for the entire amount, a plaintiff might file a partial claim to obtain a judicial ruling on key legal issues or to assess the strength of their evidence on a smaller scale before committing to a more expensive and extensive lawsuit for the full amount.
  3. Managing Costs vs. Recovery Prospects: If the total debt is very large but the defendant's financial ability to satisfy a full judgment is questionable, a partial claim might be a more pragmatic and cost-effective initial step.
  4. Simpler Proof for a Defined Portion: It might be strategically easier to gather and present conclusive evidence for a smaller, clearly demarcated portion of a larger, more complex debt, especially if different parts of the debt have different evidentiary support.

B. Potential Disadvantages and Risks

  1. Piecemeal Litigation: If the plaintiff wins the partial claim and then needs to sue for the remainder, it involves the time, effort, and expense of a second lawsuit.
  2. Complexity in Managing Statutes of Limitations: Despite the 2017 Supreme Court ruling, ensuring that the entire claim is preserved from prescription requires meticulous drafting of the partial claim complaint and consistent conduct throughout that litigation. Any ambiguity regarding the "objective manifestation of intent" to claim the whole can be fatal for the remainder's prescription.
  3. Defendant's Reaction: A defendant might perceive a partial claim as a sign of weakness, a lack of confidence in the full claim, or an overly aggressive litigation tactic, potentially making settlement negotiations more challenging.
  4. Potential for Unfavorable Precedent (Practical, not Res Judicata): While findings of fact or law in the partial claim litigation are not strictly res judicata on the distinct remainder, they could practically influence the court's or the parties' perspectives in a subsequent suit for that remainder.
  5. Defendant's Counter-Strategies: A defendant faced with a partial claim might, for example, consider filing a counterclaim for a declaratory judgment confirming the non-existence of the entire alleged debt, thereby forcing the issue of the total amount.

VI. Comparing with Common Law "Claim Splitting" Rules

The Japanese approach to express partial claims contrasts significantly with the "rule against splitting a cause of action" prevalent in many common law jurisdictions, including the U.S.

  • Under that common law rule, a plaintiff is generally required to bring all claims arising from a single "cause of action" (or, under more modern tests, the same "transaction or occurrence") in one lawsuit. If they sue for only part of such a claim, a subsequent attempt to sue for the remainder is typically barred by the doctrine of claim preclusion (res judicata).
  • Japan's acceptance of expressly reserved partial claims, where res judicata is confined to the litigated portion, offers plaintiffs a degree of flexibility not commonly found where strict claim splitting prohibitions apply.

VII. Conclusion

Filing a partial claim (ichibu seikyū) is a permissible and sometimes strategically astute option in Japanese civil procedure. For an expressly stated partial claim where the right to sue for the remainder is clearly reserved, a judgment on that initial portion generally does not create res judicata that would bar a subsequent lawsuit for the un-sued balance.

However, the impact of a partial claim on the statute of limitations for the entire underlying debt is a more complex issue. While traditionally the tolling/renewal effect was limited to the claimed portion, the Supreme Court's 2017 jurisprudence now allows for this effect to extend to the entire debt, provided the plaintiff's complaint and litigation conduct objectively and clearly manifest an intention to assert their right to the full underlying claim.

Given the critical implications for both res judicata and statutes of limitations, the decision to file a partial claim should not be taken lightly. It requires a thorough assessment of the potential benefits and risks, meticulous drafting of the complaint to clearly define the scope and reservations, and careful management of the litigation process, all undertaken in close consultation with experienced Japanese legal counsel.