De Facto Marriage Breakdown Across Borders: A Japanese Supreme Court Case on Choice of Law

Japanese Attorney at Law - Bengoshi L.L.

• 6 min read
De Facto Marriage Breakdown Across Borders: A Japanese Supreme Court Case on Choice of Law

Date of Judgment: December 27, 1961
Supreme Court of Japan, First Petty Bench

In Japan, a long-term cohabiting relationship between a man and a woman that resembles marriage but lacks formal legal registration is known as a naien. While not a formal marriage, naien relationships have been accorded certain legal protections analogous to those of a legal marriage. When such a relationship breaks down, particularly due to the fault of one party, and there are international elements involved (such as the nationality of the parties), complex questions arise as to which country's law should govern claims for damages or consolation. A Japanese Supreme Court decision from December 27, 1961, provides a significant precedent on this issue.

The Factual Background: A De Facto Marriage Undermined

The case involved a Korean man and a Korean woman residing in Japan:

  • Ms. X (Plaintiff): A Korean national.
  • Mr. Y (Defendant): Also a Korean national.
  • In December 1951, Ms. X and Mr. Y held a wedding ceremony and began what is termed a naien relationship in Japan.
  • Unbeknownst to Ms. X at the time of their engagement, Mr. Y was already in a relationship with another woman, Ms. A.
  • Throughout their cohabitation, Mr. Y continued his affair with Ms. A, frequently stayed away from home overnight, showed no affection towards Ms. X, and from around October 1953, he largely ceased to visit Ms. X.
  • Around May 1954, the situation escalated when Mr. Y brought Ms. A to Ms. X and proposed that they all live together. When Ms. X understandably objected, Mr. Y declared that even if he were to separate from Ms. X, he would not end his relationship with Ms. A.
  • Following this, on May 25, 1954, Ms. X returned to her parents' home. Efforts to find an amicable resolution failed due to Mr. Y's intransigence.
  • Ms. X subsequently sued Mr. Y, seeking consolation money (慰謝料 - isharyō) for the emotional distress caused by his wrongful termination of their naien relationship, framing her claim as a tort.

The Osaka High Court, affirming the first instance, found these facts to be established and, applying Japanese law, ruled in favor of Ms. X, awarding her consolation money. Mr. Y appealed to the Supreme Court, arguing that since both parties were Korean nationals, Korean law (their common national law) should have governed the dispute, not Japanese law.

The core issue before the Supreme Court was whether the High Court erred in applying Japanese law instead of Korean law to Ms. X's claim for consolation money arising from the breakdown of the naien relationship.

The Supreme Court's Ruling: Characterization as a Tort

The Supreme Court dismissed Mr. Y's appeal, upholding the High Court's application of Japanese law. The Court's reasoning was as follows:

  • It confirmed that Ms. X's claim, based on the overall context of her pleadings, was indeed for consolation money stemming from Mr. Y's wrongful termination of their naien relationship, which she alleged constituted a tortious act.
  • The Court accepted the lower court's factual findings regarding the wedding ceremony, the naien relationship, Mr. Y's concealment of his prior relationship, his continued affair, his neglect and lack of affection towards Ms. X, his eventual abandonment, the attempt to impose cohabitation with Ms. A, his declaration of prioritizing Ms. A, and the ultimate wrongful termination of the naien by Mr. Y.
  • The Supreme Court then delivered its key holding on the choice of law: "Viewing Mr. Y's conduct in this matter as a tort (不法行為 - fuhō kōi) against Ms. X, it goes without saying that the formation and effect of the claim arising therefrom should be governed by the law of the place where the facts constituting its cause occurred (see Article 11 of the Horei [the old Act on Application of Laws])." (Article 11 of the Horei was the general choice-of-law rule for torts, pointing to the lex loci delicti commissi. The current Act on General Rules for Application of Laws, Article 17, also addresses torts but provides a more detailed framework.)
  • Since the actions of Mr. Y that constituted the wrongful termination of the naien relationship (his abandonment, statements, etc.) all occurred in Japan, the Supreme Court concluded that the High Court was correct in applying Japanese law to adjudicate the claim.

This Supreme Court decision is significant because Japanese private international law (both the old Horei and the current Act on General Rules for Application of Laws) does not contain an explicit choice-of-law rule specifically for naien relationships.

  • The Supreme Court's Tort-Based Approach: This ruling established a precedent for treating claims for damages arising from the wrongful termination of a naien as a matter of tort law for choice-of-law purposes. This approach focuses on the wrongfulness of the act of termination and the resulting harm. Several subsequent lower court decisions have followed this path. For instance, a 2013 Tokyo District Court case similarly found that a unilateral cessation of support and termination of a relationship constituted a wrongful termination of a naien, amounting to a tort.
  • Contrast with the Prevailing Academic View: The prevailing academic opinion in Japan (the tsūsetsu) often defines naien as a union that is socially recognized as a legitimate marriage, lacking only formal registration, but which is nevertheless granted legal effects analogous to marriage (a "quasi-marriage" - 準婚, junkon). Based on this understanding, this academic view generally suggests that Japanese private international law rules concerning formal marriage should be applied to naien relationships by analogy. For a consolation money claim like the one in this Supreme Court case, this approach would typically point towards the choice-of-law rules governing the general effects of marriage (e.g., Article 27 of the Act on General Rules for Application of Laws, which prioritizes common national law or the law of common habitual residence), rather than the rules for torts. If this analogous application to marriage rules had been followed in the 1961 Supreme Court case, Korean law (the common national law of the parties) might have been applied.
  • Debate on the "Quasi-Marital" Nature: The commentary by Professor Kono accompanying this case raises pertinent questions about the factual basis for deeming certain relationships "quasi-marital." In both this Supreme Court case and some other similar cases, the relationships appeared to be fraught with problems from very early on. This prompts a deeper inquiry into what substance truly makes a naien "analogous to marriage," especially since this characterization can lead to different choice-of-law outcomes. The commentary also notes that the common definition of naien assumes a lack of formal registration, but the 2013 Tokyo District Court case involved parties who had undergone a marriage ceremony in the Philippines (though this marriage was bigamous and void for the Japanese party involved), suggesting that the substance of a marriage-like cohabitation might still be considered naien even if some form of (ineffective) ceremony occurred.
  • Inconsistent Treatment of Other Naien-Related Issues: For issues other than wrongful termination (such as paternity or property distribution after the death of one naien partner), Japanese lower courts have shown inconsistency. Some have emphasized the "quasi-marital" nature and applied marriage-related rules by analogy, while others have applied general family law rules or specific rules based on the nature of the asset (e.g., situs law for property). These varied approaches highlight the lack of a unified framework for naien in Japanese private international law.
  • Comparison with Broken Engagements: Similar to naien, there are no specific private international law rules for broken engagements (婚約破棄 - kon'yaku haki). Courts and scholars have debated whether to apply rules analogous to marriage formation or more general family relations rules. The relationship between the choice-of-law approaches for broken engagements and terminated naien relationships requires further coherent development, as these situations can be factually intertwined.
  • An Alternative Scholarly Perspective: No Special PIL Category for Naien: Some legal scholars argue against establishing naien as a distinct category for choice-of-law purposes. Instead, they propose that legal issues arising from such relationships should be addressed by applying the standard choice-of-law rules relevant to the specific claim being made (e.g., tort law for damages, contract law for agreements, property law for assets). This perspective would find the Supreme Court's tort-based characterization in the 1961 case to be appropriate. Proponents of this view question the utility of a vague "analogous to marriage" concept for naien in private international law, especially given the diverse forms of cohabiting relationships and partnerships recognized globally today.

Conclusion

The Supreme Court's 1961 decision remains a key reference point in Japanese private international law for claims arising from the wrongful termination of a naien relationship involving foreign nationals. By characterizing such claims as torts, the Court directed the application of the law of the place where the wrongful acts occurred, which in this instance was Japan. This ruling highlights one approach to navigating the absence of specific statutory choice-of-law rules for de facto marriages. However, as academic commentary suggests, the debate continues regarding the most appropriate way to characterize naien relationships in the context of private international law, the coherence of this approach with other related areas like broken engagements, and the need to consider the evolving landscape of relationship recognition worldwide.