Multiple Claims in a Single Lawsuit in Japan: How is the Total Value Calculated?

Japanese Attorney at Law - Bengoshi L.L.

01 Jun 2025 • 10 min read

In the Japanese civil litigation system, it's common for a plaintiff to assert multiple claims against a defendant within a single lawsuit. This practice, known as joinder of claims (seikyū no heigō or, in the context of multiple parties, kyōdō soshō), offers efficiency by allowing related matters to be resolved in one proceeding. However, it raises a critical question for procedural purposes: how is the total "Sogaku" (the value of the subject matter of the action) determined when several claims are combined? The answer is vital, as the "Sogaku" directly impacts which court has jurisdiction and the amount of court filing fees. This article will explain the general rule of aggregation for joined claims and, crucially, detail the significant exceptions that can alter this calculation.

The General Rule: Aggregation of Claim Values (原則：合算 - Gassan)

As a fundamental principle, when multiple claims are pursued together in one lawsuit, the total "Sogaku" is calculated by aggregating, or summing up, the individual "Sogaku" of each distinct claim. This rule is primarily derived from Article 9, Paragraph 1 (main text) of Japan's Code of Civil Procedure (Minji Soshō Hō, Act No. 109 of 1996).

This principle applies regardless of whether the joinder is:

Objective Joinder (Seikyū no Heigō): Where a single plaintiff asserts multiple claims against a single defendant (governed by Article 136 of the Code of Civil Procedure). For example, a supplier might sue a buyer for the unpaid price of goods delivered (Claim A) and separately for damages arising from a different breach of the same contract (Claim B).
Subjective Joinder (Kyōdō Soshō): Where multiple plaintiffs jointly sue, or a plaintiff sues multiple defendants, provided the conditions for such joinder under Article 38 of the Code of Civil Procedure are met.

The rationale behind the aggregation rule is that the court is being asked to adjudicate each claim, and the total economic interest at stake for the plaintiff (or plaintiffs collectively) is the sum of the values of these individual interests. Each claim represents a distinct demand for a judicial determination and potential enforcement.

For instance, if a company files a lawsuit asserting:

Claim 1: Unpaid contractual amount of 5,000,000 yen.
Claim 2: Damages for a separate instance of defective performance amounting to 3,000,000 yen.
The total "Sogaku" for determining jurisdiction and initial court fees would generally be 5,000,000 yen + 3,000,000 yen = 8,000,000 yen.

It is worth noting a practical aspect concerning the initial acceptance of a case. If a plaintiff presents a complaint with joined claims, court clerks at the acceptance stage will typically calculate fees based on the plaintiff's asserted joinder. If, later in the proceedings, the court determines that the claims were improperly joined (i.e., do not meet the legal requirements for joinder), it may order a separation of the proceedings. At that point, fee adjustments might be necessary, potentially requiring additional fees for the newly separated actions. However, for the initial filing, the aggregation based on the plaintiff's presentation is common.

While aggregation is the default, there are crucial exceptions designed to prevent an artificial inflation of the "Sogaku" and to reflect the true economic substance of the dispute.

Exception 1: The Principle of Non-Inclusion of Ancillary Claims (附帯請求不算入の原則 - Futaiseikyū Fusannyū no Gensoku)

The most frequently encountered exception to the aggregation rule is the non-inclusion of "ancillary claims" (futaiseikyū). Article 9, Paragraph 2 of the Code of Civil Procedure provides that the value of claims for fruits, damages, penalties, or expenses that are asserted as ancillary to a principal claim shall not be included in the calculation of the "Sogaku" of the suit.

What constitutes an ancillary claim? These are claims inherently dependent on, or incidental to, a main or principal claim. Their existence and value often flow directly from the resolution of the principal claim. Common examples include:

Interest (利息 - risoku): Accrued interest on a principal monetary debt.
Damages for Delay (遅延損害金 - chien songaikin): Compensation for late payment or performance.
Rent or Usage Fees for Continued Occupation (賃料・使用損害金 - chinryō / shiyō songaikin): For example, if a landlord sues for eviction and also claims rent arrears up to the eviction, and compensation for the tenant's continued use of the property from the termination of the lease until actual surrender.
Contractual Penalties (違約金 - iyakukin): Pre-agreed sums payable upon breach of contract, when claimed alongside the main performance.
Expenses (費用 - hiyō): Certain types of expenses directly related to the principal claim, though typically, general litigation costs are handled separately by the court at the conclusion of the case. The "expenses" referred to here are more likely pre-litigation costs directly caused by the defendant's conduct related to the principal claim, if claimed as part of the substantive relief.

The Rule: When these types of claims are made together with a principal claim, their individual monetary values are not added to the "Sogaku" of that principal claim. The "Sogaku" of the entire suit (or that portion of it) is determined solely by the value of the principal claim.

Rationale: This rule serves several practical purposes:

Preventing Disproportionate "Sogaku": Ancillary claims like interest or damages for delay can accumulate significantly over time. Including them in the "Sogaku" could inflate the value of the suit to a level that misrepresents the core economic dispute, potentially pushing a case into a higher court tier unnecessarily or making filing fees prohibitively expensive.
Simplification: It simplifies the "Sogaku" calculation by focusing on the primary object of the dispute.
Predictability: It offers greater predictability regarding jurisdictional thresholds and initial costs.

Crucial Clarification – Independent Claims:
It is vital to understand that if these items (interest, damages, etc.) are claimed independently, without an accompanying principal claim, they are no longer considered ancillary for "Sogaku" purposes. In such a scenario, their full value is calculated to determine the "Sogaku." For example, if a creditor has already recovered the principal debt but files a separate lawsuit solely for accrued unpaid interest, the amount of that interest will form the "Sogaku" of this new action.

Example: A company sues for the recovery of a loan principal of 20,000,000 yen. It also claims 2,000,000 yen in accrued contractual interest and 1,500,000 yen in damages for delayed payment.
Under the ancillary claim rule, the "Sogaku" of this lawsuit would be 20,000,000 yen (the principal amount). The 2,000,000 yen interest and 1,500,000 yen delay damages would not be added for "Sogaku" calculation.

Exception 2: Claims with a Common Economic Interest (経済的利益の共通 - Keizaiteki Rieki no Kyōtsū) – The Absorption Rule (吸収関係 - Kyūshū Kankei)

Another significant exception to the aggregation rule arises when multiple joined claims, despite being legally distinct, essentially aim to secure the same underlying economic interest for the plaintiff. This principle is found in the proviso to Article 9, Paragraph 1 of the Code of Civil Procedure, which states that if the interests asserted by multiple claims are common, their values are not aggregated. Instead, the "Sogaku" is determined by the highest value among those interrelated claims. This is often referred to as an "absorption rule" (kyūshū kankei), where the claim with the highest value effectively "absorbs" the others for "Sogaku" purposes.

Rationale: The core idea is that the plaintiff ultimately seeks to achieve a single economic outcome or protect a singular economic interest, even if they are asserting this through various legal avenues or alternative prayers for relief. To add the values of all such claims would artificially inflate the "Sogaku" beyond the actual economic benefit the plaintiff stands to gain.

Several types of joinder fall under this exception:

a. Simple Joinder with a Common Economic Interest (Tanjun Heigō Seikyū no Uchi Keizaiteki Rieki Kyōtsū)

This occurs when distinct legal claims are made, but their successful outcome leads to the same ultimate economic benefit.

Example 1: Confirmation of Ownership and Delivery of the Same Property. If a plaintiff sues for a judgment confirming their ownership of a specific piece of equipment and, in the same lawsuit, also demands the delivery (surrender) of that same equipment from the defendant. The ultimate economic interest is gaining undisputed ownership and possession of the equipment. Here, the "Sogaku" would typically be the value of the ownership claim (e.g., the market value of the equipment), as the claim for delivery, if valued separately under "Sogaku Notification" guidelines (often half the property's value), would usually be lower and thus absorbed.
Example 2: Suing a Principal Debtor and a Joint-and-Several Guarantor. A lender sues the primary borrower for a 10,000,000 yen loan and, in the same action, also sues a person who provided a joint-and-several guarantee for that same 10,000,000 yen loan. The lender's economic interest is the recovery of the 10,000,000 yen (plus any ancillary interest/damages, which are treated separately). The lender cannot recover the principal sum twice. Thus, the "Sogaku" is 10,000,000 yen, not 20,000,000 yen.

b. Principal Claim and Alternative (Compensatory) Claim (Shuiteki Seikyū to Daishō Seikyū)

This involves a primary claim for a specific performance (e.g., delivery of a unique asset) and an alternative claim for monetary damages if the primary performance is impossible.

Example: Delivery of a Custom-Made Machine or Damages. A company sues for the delivery of a specially manufactured machine valued at 50,000,000 yen. As an alternative, if delivery proves impossible (e.g., the machine was destroyed), the company claims 50,000,000 yen in damages. The plaintiff seeks either the machine or its monetary equivalent, not both. The "Sogaku" would be 50,000,000 yen (the higher of the two, which are the same in this instance). If the damages claim was for a different amount (e.g., reflecting additional losses), the higher figure would be used.

c. Principal Claim and Subsidiary/Preliminary Claim (Shuiteki Seikyū to Yobiteki Seikyū)

Here, the plaintiff makes a primary claim, and if that claim fails for a particular reason, a secondary (subsidiary or preliminary) claim is triggered.

Example: Payment under a Contract vs. Return of Goods. A seller sues for the purchase price under a contract. As a subsidiary claim, if the court finds the contract to be invalid (e.g., due to lack of capacity), the seller then claims the return of the goods that were delivered under the purported contract. The plaintiff is pursuing one outcome (payment) or, failing that, another (return of goods). The "Sogaku" is based on the claim that has the higher value.

d. Disjunctive/Alternative Joinder of Claims (Sentakuteki Heigō ni Kakaru Sūko no Seikyū)

This is where the plaintiff asserts multiple legal grounds for the same ultimate relief, and any one of them being successful would satisfy the plaintiff's objective.

Example: Eviction Based on Ownership OR Lease Termination. A landlord sues to evict a tenant. The claim for eviction is based, firstly, on the landlord's ownership right and, alternatively, on the ground that the lease agreement has been validly terminated. The ultimate economic relief sought is the recovery of possession of the property. The "Sogaku" would be based on the single act of recovering possession, typically valued according to rules for property surrender claims.

e. Claims in Cases of "Similar Necessary Joinder of Parties" (Ruiji Hitsuyōteki Kyōdō Soshō)

This refers to situations where multiple parties must sue or be sued jointly due to the nature of the legal relationship, and the outcome must be consistent for all of them.

Example: Multiple Shareholders Annulling a Resolution. If several shareholders jointly file an action to nullify a specific shareholder resolution (e.g., under former Commercial Code Article 252). Although such a claim is often treated as non-monetary (attracting a deemed "Sogaku" of 950,000 yen), the "interest" in having that resolution nullified is singular for the group of plaintiffs acting in this joint capacity. The deemed "Sogaku" of 950,000 yen would apply once to this collective claim, not multiplied by the number of such shareholders. The interest is indivisible among them in this context.

A specific rule, found in Article 4, Paragraph 3 of the Costs Act, governs the joinder of a claim not concerning property rights with a claim concerning property rights when both claims arise from the same factual cause.

The Rule: In such cases, the "Sogaku" for calculating court fees is the value of the higher of the two claims. The values are not aggregated.

Example:

A plaintiff files for divorce (a non-monetary claim, with a deemed "Sogaku" of 950,000 yen).
In the same lawsuit, the plaintiff also claims solatium (damages for emotional distress) of 5,000,000 yen, arising from the same facts that constitute the grounds for divorce.
The "Sogaku" for the combined lawsuit for fee purposes would be 5,000,000 yen (the value of the monetary claim, as it is higher than the 950,000 yen deemed value of the non-monetary claim).
Conversely, if the solatium claim was for 500,000 yen, the "Sogaku" for the combined lawsuit would be 950,000 yen (the deemed value of the non-monetary claim, as it is higher).

Rationale: This rule aims to provide a reasonable "Sogaku" when intimately related monetary and non-monetary issues, stemming from a single underlying dispute, are litigated together. It prevents the "Sogaku" from being unduly inflated by simply adding the deemed value of the non-monetary claim to the full value of the related monetary claim, recognizing their interconnectedness.

Practical Application and Strategic Considerations

The rules governing "Sogaku" in cases of joined claims have direct practical consequences:

Complaint Drafting: Litigants and their counsel must carefully consider these rules when drafting a complaint that includes multiple claims. The way claims are framed can influence the "Sogaku" calculation.
Cost Management: An accurate understanding allows for better prediction of initial court filing fees, which can be substantial in high-value multi-claim litigation.
Jurisdictional Strategy: The total "Sogaku" will determine whether the case falls within the jurisdiction of a Summary Court or a District Court. While ethical considerations are paramount, parties may strategically consider the scope and manner of joinder based on their preferred forum, within the bounds of the law. For instance, deciding whether to include smaller, ancillary monetary items as independent claims (if permissible) or to rely on their ancillary nature might be a tactical choice in some scenarios, though the rules on ancillary claims are fairly clear-cut.
Valuation of Individual Claims: Before applying any joinder rules, each individual claim must first be properly valued according to its own nature (monetary, non-monetary, specific statutory rules, etc.). Only then can the rules of aggregation, non-inclusion, or absorption be applied to the joined set.

Conclusion: Navigating Complexity with Precision

Calculating the "Sogaku" in lawsuits involving multiple claims in Japan requires careful attention to both the general principle of aggregation and its significant exceptions. The non-inclusion of ancillary claims and the absorption rule for claims sharing a common economic interest are designed to ensure that the "Sogaku" accurately reflects the true economic stake of the litigation and that court fees are assessed fairly.

For businesses involved in or contemplating complex litigation in Japan, a precise understanding of these valuation rules is indispensable. It directly impacts upfront costs, influences jurisdictional considerations, and can subtly shape overall litigation strategy. Given the nuances involved, particularly in distinguishing ancillary claims or identifying common economic interests across legally distinct prayers for relief, consulting with experienced Japanese legal counsel is highly recommended. Such expertise can ensure that claims are appropriately valued and joined, setting a sound procedural foundation for the resolution of the dispute.