Assisting a Party in Japanese Litigation (Auxiliary Intervention): What Are the Court Fees for Interveners and Their Appeals?

In the complex web of civil litigation, the outcome of a lawsuit between two primary parties can often have significant legal or economic repercussions for third parties who are not directly involved as plaintiffs or defendants. Japanese civil procedure, under Articles 42 through 46 of the Code of Civil Procedure (CCP), provides a mechanism for such interested third parties to participate in the litigation to protect their interests. This is known as "auxiliary intervention" (補助参加 - hojo sanka). Unlike an independent party intervener who asserts their own claims, an auxiliary intervener joins to assist one of the existing litigants. This distinct role has specific, and generally modest, implications for court filing fees, though complexities can arise if the intervener files an appeal.

The Nature and Purpose of Auxiliary Intervention (Hojo Sanka)

Auxiliary intervention allows a third party who has a legal interest in the outcome of a pending lawsuit to join the proceedings in support of one of the main parties (either the plaintiff or the defendant). This party whom the intervener supports is referred to as the "assisted party" (被参加人 - hi-sankanin).

Key Characteristics:

• No Independent Claims: The auxiliary intervener does not bring their own claims for relief against any party. Their role is supportive, aimed at helping the assisted party achieve a favorable judgment.
• Legal Interest Required (CCP Art. 42): The basis for intervention is a demonstrable legal interest in the result of the suit. This interest is often indirect; for example, a guarantor might intervene to support a debtor, as a judgment against the debtor could lead to the guarantor being called upon to pay. Similarly, an indemnitor might intervene to assist an indemnitee.
• Rights of the Auxiliary Intervener (CCP Art. 45): Once admitted, an auxiliary intervener can generally perform most procedural acts to support the assisted party, such as making arguments, submitting evidence, and filing motions. However, their actions are generally subordinate to those of the assisted party; they usually cannot take actions that contradict the explicit will or actions of the party they are assisting.
• Binding Effect of Judgment (Intervention Effect - 参加的効力, sanka-teki kōryoku) (CCP Art. 46): A crucial aspect is that the auxiliary intervener is generally bound by the findings and outcome of the main judgment in any subsequent legal relationship between themselves and the party they assisted. This "intervention effect" is often the primary motivation for intervening – to ensure their voice is heard and to be bound only by a judgment they had a chance to influence.

Court Fees for the Initial Act of Auxiliary Intervention

Given that an auxiliary intervener is not asserting their own claim for a quantifiable "value of suit" (so'gaku) but is merely seeking to participate in an existing dispute to support a party, the court fee for the application to intervene is nominal.

• Fixed Nominal Fee: The fee for filing an application to become an auxiliary intervener is a small, fixed sum. According to the source material, this is ¥500, as stipulated in the Civil Procedure Costs Act, Appended Table 1, Item 17, sub-item Ro (ニ).

This low fee reflects the supportive, non-claim-asserting nature of auxiliary intervention, distinguishing it significantly from independent party intervention where the intervener brings their own claims and pays fees based on the so'gaku of those claims.

Court Fees When an Auxiliary Intervener Files an Appeal

An auxiliary intervener generally has the right to file an appeal if the judgment is unfavorable to the party they assisted, even if the assisted party themselves chooses not to appeal. This is a key right that allows the intervener to continue protecting their indirect interests at the appellate level. The calculation of court fees for such an appeal, however, follows specific principles.

A. Determining the "Value of Suit" (So'gaku) for the Appeal

The central principle for determining the so'gaku when an auxiliary intervener files an appeal is that it is not based on any independent financial or legal interest of the auxiliary intervener themselves.

Instead, the so'gaku for the appeal is determined exclusively by the scope of dissatisfaction of the assisted party (hi-sankanin) with the judgment of the lower court. The auxiliary intervener, in filing the appeal, is essentially stepping into the assisted party's shoes to challenge the unfavorable aspects of the judgment as they pertain to the assisted party's original claims or defenses.

• Example: If an assisted plaintiff had claimed ¥10 million but was only awarded ¥2 million (or their claim was entirely dismissed), and the auxiliary intervener appeals seeking the full ¥10 million (or the portion denied) on behalf of the plaintiff, the "value of suit" for the appeal would be based on the ¥8 million (or ¥10 million) that represents the plaintiff's dissatisfaction, not on some separate valuation of the intervener's indirect interest.

The appeal fee is then calculated based on this so'gaku (representing the assisted party's dissatisfaction) according to the standard appellate fee schedule (typically 1.5 times the first-instance fee for that so'gaku).

B. The "Double Appeal" (二重控訴 - Nijū Kōso) Scenario

A procedural question arises if both the assisted party and their auxiliary intervener decide to file separate appeals against the same unfavorable judgment, covering the same grounds of dissatisfaction.

• Prevailing Theory (Tsūsetsu) mentioned in the source material: Prevailing legal theory in Japan often considers this situation a "double appeal" (or duplicative appeal). The consequence under this view is typically that the appeal filed later should be dismissed as improper to avoid redundant proceedings.
• Author's Critique of Dismissing as "Double Appeal": The author of the source text expresses disagreement with this characterization and the outcome of dismissal. It is argued that when both the assisted party and the auxiliary intervener appeal the same aspects of a judgment, their appeals are not truly a problematic "double appeal" but are, in substance, "one and the same" (一体であり - ittai de ari), directed towards achieving the same corrective goal for the assisted party. The author notes that German law, for instance, tends to support the idea of treating such concurrent appeals as unified rather than dismissing one.
• Implications for Fees in Concurrent Appeals: If the author's view (that such appeals are unified) were followed for fee purposes, it would logically imply that only one set of appeal fees should be payable, calculated based on the single scope of the assisted party's dissatisfaction, irrespective of whether one or both technically filed a notice of appeal. The system ideally should not impose double fees for what is effectively a single appellate challenge concerning the assisted party's rights. However, if the prevailing procedural view leads to the dismissal of one appeal, the fee issue for the dismissed appeal might become moot, with fees being based on the one appeal that is allowed to proceed.

Conclusion

Auxiliary intervention provides a valuable avenue for third parties with legal interests to participate in and influence Japanese civil litigation without asserting their own direct claims. The initial court fee for joining as an auxiliary intervener is nominal (¥500 as per the source material ), reflecting their supportive role. If an auxiliary intervener exercises their right to appeal an unfavorable judgment on behalf of the assisted party, the "value of suit" for that appeal, and thus the court fee, is determined by the scope of the assisted party's dissatisfaction with the lower court's decision. While the procedural handling of concurrent appeals by both the assisted party and the intervener has been a subject of some theoretical debate, the principle remains that the appeal focuses on rectifying the outcome for the assisted party, and fee calculations should align with that core objective.