How Does Japanese Law Define "Infringement of Rights or Legally Protected Interests" in Tort Cases?

A fundamental element for establishing tort liability under Article 709 of the Japanese Civil Code is the "infringement of any right of others, or legally protected interest of others." This phrase, particularly the inclusion of "legally protected interests" following a 2004 amendment, represents a significant evolution in Japanese jurisprudence. Understanding how this concept is defined and applied is crucial for assessing potential tort claims in Japan.

The Starting Point: Limiting Tort Liability

Historically, the requirement of "infringement of rights" (権利侵害 - kengai shingai) in the pre-2004 Civil Code was intended to circumscribe the scope of tortious liability. In the early period after the Civil Code's enactment (1896), Japanese courts and scholars generally adopted a strict interpretation. Liability was typically confined to cases where an established, clearly defined legal right—such as property rights or specific personal rights like bodily integrity—had been violated.

Interests that were not explicitly recognized as "rights" within the existing legal framework often failed to secure protection under tort law. An illustrative example from this era is a Taishin-in (Great Court of Cassation, the highest court at the time) judgment from July 4, 1914 (Keiroku 20-1360). This case, often referred to as the Kumoemon case, involved the unauthorized reproduction of a rōkyoku (a type of narrative singing) performance. The court denied protection, reasoning that the improvised and non-standardized nature of the performance did not qualify for copyright protection, and thus, no "right" had been infringed in a way that tort law would recognize for damages beyond copyright.

A Pivotal Shift: The Daigaku-yu Case and the Embrace of "Legally Protected Interests"

The strict interpretation began to evolve, and a significant turning point came with the Taishin-in judgment of November 28, 1925, in what is commonly known as the Daigaku-yu case (Minshu 4-670).

This case involved a dispute concerning a public bathhouse named "Daigaku-yu." The original owner (Y) had leased the bathhouse building to X and also sold X the goodwill associated with the established name "Daigaku-yu." Later, after the lease was consensually terminated, Y leased the same building to D, who then began operating a bathhouse under the same name, "Daigaku-yu." X sued Y and D for damages. The core issue was whether the value of the established business name or the profits X could have made from its sale were interests protected by tort law.

The lower court, adhering to a stricter view, had ruled against X, finding that the "established name" was not a "right." However, the Taishin-in reversed this. It held that even if an interest did not strictly qualify as a "right" in the same rigorous sense as established property rights, it could still be protected if it was a "legally protected interest" (法律上保護セラルヽ利益 - hōritsujō hogo seraru beki rieki). This marked a crucial "relaxation of the content of rights" (権利内容の緩和 - kenri naiyō no kanwa). Furthermore, the Taishin-in reinterpreted the then-Article 709 as having a broader meaning, encompassing any act that contravened legal norms and thereby caused harm to another. The focus of the infringement was seen not just as the "established name" itself, but the "benefit that could have been obtained" (得べかりし利益 - ubekarishi rieki) from the sale of that goodwill.

From "Infringement of Rights" to "Illegality" (Illegality as the Core Concept)

The judicial expansion initiated by cases like Daigaku-yu spurred academic discourse that increasingly shifted the focus from a narrow "infringement of rights" to a broader concept of "illegality" (違法性 - ihōsei) as the core objective element of a tort.

Two prominent scholars heavily influenced this shift:

1. Professor Suekawa Hiroshi (末川博): He argued that the essence of tort liability lay in compensating for damages suffered due to an "illegal act" (違法行為 - ihō kōi) committed with intent or negligence. From this perspective, the "infringement of a right" was merely one indicator (徴表 - chōhyō) or manifestation of such illegality. Professor Suekawa contended that the fundamental issue was the breach of the "legal order" (法律秩序 - hōritsu chitsujo), and thus, even without a clear "infringement of a right," illegality—and therefore tort liability—could arise from violations of statutes or acts contrary to public order and good morals.
2. Professor Wagatsuma Sakae (我妻栄): Building on Professor Suekawa's foundation, Professor Wagatsuma further analyzed the components of "illegality" and refined its analytical framework. He proposed the influential "correlation theory" (相関関係論 - sōkan kankeiron). According to this theory, the existence of "illegality" (which was seen as replacing "infringement of rights" as a key requirement) is determined by assessing the correlation between:
   • The nature of the interest infringed (e.g., absolute property rights, personality rights, contractual rights).
   • The manner of the infringing act (e.g., violation of criminal statutes, prohibitory regulations, public order, abuse of rights).
     A balancing of these two factors would determine whether the conduct was "illegal."

This view, particularly the correlation theory, gained widespread acceptance and became the prevailing approach in Japanese judicial practice and academic circles for a considerable period, influencing, for instance, the wording of Article 1 of the State Redress Act (国家賠償法), which refers to an official "illegally" causing damage.

Refinements, Critiques, and Alternative Approaches

Over time, the dominant "illegality" framework, especially the correlation theory, faced scrutiny and alternative perspectives emerged.

The "Tolerance Limit" Theory (受忍限度論 - Junin Gendo Ron)

Primarily developed in the context of nuisance and environmental pollution cases, the "tolerance limit" theory (受忍限度論) offered a more nuanced approach to determining illegality. Proponents criticized the correlation theory for often focusing too narrowly on only two factors (type of interest and manner of infringement). Instead, the tolerance limit theory argued that a comprehensive assessment of various factors was necessary to determine if the harm inflicted exceeded a socially acceptable "tolerance limit." These factors included:

• The nature and extent of the infringed interest.
• The character of the locality.
• The victim's prior knowledge.
• The chronological order of land use.
• The availability and implementation of best practical methods or reasonable preventive measures.
• Other social values and necessities.
• Special circumstances of the victim.
• Governmental permits or approvals.
• Compliance with statutory standards.

If the harm, considered in light of these multifaceted factors, surpassed what a member of society should reasonably be expected to endure, the conduct causing it would be deemed illegal. It's worth noting that this theory later evolved into the "new tolerance limit theory," which often incorporated these considerations into the assessment of "negligence" rather than as a standalone "illegality" element.

The "Illegality Requirement is Unnecessary" Theory (「違法性」要件不要論 - Ihōsei Yōken Fuyō Ron)

From the late 1970s onwards, a significant critique of the "illegality" theories gained traction, arguing that a separate "illegality" requirement, distinct from "infringement of rights" and "intent/negligence," was unnecessary and not explicitly mandated by the text of Article 709. This perspective highlighted two main points:

1. If the aim was simply to broaden the scope of "rights" to include "legally protectable interests," one could achieve this by interpreting the term "rights" in Article 709 expansively. There was no need to introduce an extra-statutory requirement of "illegality." The original function of the "infringement of rights" requirement—to limit the scope of torts—would naturally be diluted if "rights" encompassed all legally worthy interests.
2. The balancing of the infringed interest and the manner of infringement, which the correlation theory addressed under "illegality," could be more appropriately handled within the assessment of "intent or negligence."

Under this view, the analytical work done by the "illegality" requirement could be sufficiently covered by the "infringement of rights (or legally protected interests)" and "intent or negligence" elements, rendering a distinct "illegality" element superfluous. Supporters of this view also pointed out that while the German Civil Code (e.g., §823(1)) explicitly requires an "illegal" infringement of certain absolute rights, Article 709 of the Japanese Civil Code lacks such explicit wording, suggesting that "illegality" as a separate, overarching requirement might be a concept more specific to German law.

The Resurgence of "Rights" Theory: Re-evaluating "Infringement of Rights" (「権利」論の再生 - Kenri Ron no Saisei)

In more recent years, there has been a renewed focus on the "infringement of rights" element itself. While the expansion to "legally protected interests" is well-established, some scholars have advocated for a "rights approach" (権利アプローチ - kenri apurōchi) that seeks to ground the protection offered by tort law more explicitly in the hierarchy of fundamental rights guaranteed by the Japanese Constitution.

This approach emphasizes that a primary purpose of tort law is to provide remedies for infringements of rights guaranteed by the overall legal order, with the Constitution at its apex. Therefore, determining what constitutes a protectable "right" or "legally protected interest" under Article 709 should involve a consideration of what rights are recognized and protected for individuals in contemporary society from a constitutional perspective.

From this viewpoint, the element of the tortfeasor's "negligence" is often analyzed as a permissible limitation on the tortfeasor's own fundamental right to freedom of action (which is also a constitutionally protected interest, encompassing freedoms like business activity and choice of occupation). The adjudication of a tort claim then becomes a balancing act between the need to protect the victim's infringed right and the need to not unduly restrict the tortfeasor's freedom of action, guided by principles of proportionality (avoiding both excessive intervention and under-protection).

The 2004 Civil Code Amendment: Codifying an Evolved Understanding

The developments in case law and academic theory culminated in the 2004 amendment to the Civil Code, effective April 1, 2005. Article 709 was revised to explicitly state that liability arises for one who "has intentionally or negligently infringed a right of another person, or a legally protected interest of another person" (他人の権利又は法律上保護される利益を侵害した者 - tanin no kenri matawa hōritsujō hogo sareru rieki o shingai shita mono). The previous wording was simply "infringed the rights of another" (他人ノ権利ヲ侵害シタル者 - tanin no kenri o shingai shitaru mono).

This amendment is widely understood not as introducing a radically new rule, but rather as codifying the interpretation of "rights" that had already been established by the judiciary since the Daigaku-yu case—an interpretation that included "legally protected interests." Given the diverse academic theories surrounding the concept of "rights" and "illegality," the amended wording "right... or a legally protected interest" was chosen carefully. It aimed to avoid potential confusion or misinterpretation that might arise from retaining the word "rights" alone and was designed to be compatible with various prevailing scholarly viewpoints, essentially allowing different theories to explain the amended text from their own perspectives.

Illustrative Applications in Japanese Case Law

The broad understanding of "legally protected interests" is evident in how Japanese courts have applied tort principles in various contexts:

• Infidelity (Adultery):
  Japanese courts have held that a third party who engages in an extramarital affair with a married individual can be liable in tort to the other spouse. Such conduct is typically seen as infringing the non-consenting spouse's "right or legally protected interest in the maintenance of a peaceful marital relationship" (婚姻共同生活上の平和の維持という権利又は法的保護に値する利益 - kon'in kyōdō seikatsu jō no heiwa no iji to iu kenri matawa hōteki hogo ni atai suru rieki), and the act is generally deemed illegal if committed intentionally or negligently (e.g., Supreme Court, March 30, 1979, Minshu 33-2-303). However, an important exception exists: if the marital relationship had already irretrievably broken down at the time of the affair, the third party generally bears no tort liability, as there is no longer a legally protected interest in marital peace to infringe (e.g., Supreme Court, March 26, 1996, Minshu 50-4-993).
• Breach of Good Faith in Contract Negotiations:
  Conduct during the contract negotiation phase can also give rise to tort liability. Examples include:
  • Providing false or misleading information or definitive but unfounded judgments, leading the other party to enter into a contract (breach of duties of explanation or information provision).
  • Failing to point out a misunderstanding that one party notices the other party is laboring under.
  • Unjustifiably breaking off negotiations at a very advanced stage, contrary to prior conduct (improper termination of contract negotiations).
  • Selling an unsuitable product to someone demonstrably lacking in experience or knowledge relevant to the transaction (e.g., violation of the suitability principle in investment transactions).
    In such cases, the aggrieved party may claim damages in tort, often on the grounds that their right to self-determination in deciding whether and on what terms to conclude a contract has been infringed. While historically sometimes categorized under a quasi-contractual "culpa in contrahendo" (fault in negotiation) theory, contemporary Japanese case law predominantly treats these as torts.

Conclusion

The definition of what constitutes an "infringement of rights or legally protected interests" in Japanese tort law has evolved significantly from a narrow focus on formally recognized rights to a more flexible and encompassing approach. This evolution, driven by landmark judicial decisions like the Daigaku-yu case and extensive academic debate involving concepts like "illegality" and "tolerance limits," was formally recognized in the 2004 amendment to Article 709 of the Civil Code.

Today, the inquiry involves identifying whether an interest warrants legal protection under tort law, a determination that often involves a careful balancing of competing interests and societal values. This dynamic interpretation ensures that tort law can adapt to protect emerging interests in an ever-changing society, while still adhering to its foundational principles.