Q: What is the scope of "judicial power" in Japan, and what constitutes a "legal dispute" justiciable by the courts? What are the limits to judicial power?

Japanese Attorney at Law - Bengoshi L.L.

• 8 min read

The judiciary stands as a crucial pillar in any constitutional democracy, entrusted with the interpretation and application of law, the resolution of disputes, and often, the safeguarding of constitutional principles. Under the Constitution of Japan, "the whole judicial power" (shihōken - 司法権) is vested in the Supreme Court and in such inferior courts as are established by law (Article 76, paragraph 1). But what precisely does this "judicial power" entail? What kinds of controversies fall within its ambit as "legal disputes" suitable for court adjudication? And, importantly, what are the recognized boundaries or limitations to this power? This article explores these fundamental questions concerning the scope and limits of judicial power in Japan.

The Nature and Breadth of Judicial Power in Japan

The post-WWII Constitution marked a significant departure from the Meiji era concerning the judiciary. Under the Meiji Constitution, judicial power was more circumscribed, administrative disputes were largely handled by separate administrative courts, and ordinary courts lacked the authority to review the constitutionality of laws. The current Constitution, influenced by Anglo-American legal thought, established a unified judicial system and broadened the conception of judicial power.

The prevailing understanding is that "judicial power" in Japan encompasses the authority to adjudicate all "legal disputes" (hōritsujō no sōshō - 法律上の争訟). This is explicitly stated in Article 3, paragraph 1 of the Court Act, which declares that courts shall "decide all legal disputes, except those otherwise specially provided for in the Constitution." This includes civil, criminal, and administrative cases, all falling under the jurisdiction of the ordinary court system. The traditional definition of judicial power, often cited from the works of jurist Shirō Kiyomiya (清宮四郎), describes it as "the state's function of adjudicating specific disputes by applying and declaring the law."

For a matter to be considered a "legal dispute" justiciable by Japanese courts, it generally must satisfy two core requirements, consistently articulated by the Supreme Court and its administrative guidance:

  1. A Concrete Dispute Concerning Specific Rights, Duties, or Legal Relations (Gutaiteki Kenri Gimu Yōken - 具体的権利義務要件):
    This means the courts do not issue advisory opinions or rule on abstract or hypothetical legal questions. There must be an actual, existing controversy between specific parties concerning their legal rights, duties, or the status of their legal relationships. A mere academic disagreement or a general political grievance does not suffice. The Supreme Court, for example, in the Police Reserve Unconstitutionality Case (Grand Bench judgment, October 8, 1952 [Shōwa 27]), refused to rule on the abstract constitutionality of the National Police Reserve, finding no concrete legal dispute affecting the plaintiff's specific rights.
  2. A Dispute Resolvable Through the Application of Law (Shūkyokuteki Kaiketsu Kanōsei Yōken - 終局的解決可能性要件):
    The controversy must be one that the courts can definitively resolve by interpreting and applying existing legal norms. If a dispute turns solely on matters of religious dogma, purely political expediency, highly specialized technical judgment lacking legal standards, or subjective academic evaluation, it may be deemed non-justiciable because the court lacks the legal tools to render a final and binding legal judgment. The Supreme Court's decision in a case concerning the authenticity of a Buddhist religious object (the “Itamandala” Case, Grand Bench judgment, April 7, 1981 [Shōwa 56]) illustrates this, where the Court declined jurisdiction as the core issue required an interpretation of religious doctrine, not law.

Beyond Individual Rights: Objective Litigation and Non-Contentious Cases

While the core of judicial power lies in resolving disputes over individual rights and duties (subjective litigation), Article 3, paragraph 1 of the Court Act also acknowledges that courts may have "such other powers as are specially provided for by law." This allows for:

  • Objective Litigation (Kyakkan Soshō - 客観訴訟): These are lawsuits aimed at ensuring the general legality of administrative actions or the proper functioning of public institutions, rather than protecting a specific plaintiff's individual legal interest. They are permissible only when explicitly authorized by statute. Examples include:
    • Popular actions (minshū soshō - 民衆訴訟), such as election invalidation lawsuits brought by voters (e.g., challenging vote-value disparity) or taxpayer lawsuits under the Local Autonomy Act challenging allegedly illegal expenditures by local governments.
    • Inter-organ disputes (kikan soshō - 機関訴訟), which are lawsuits between different state or local government organs concerning their respective powers.
  • Non-Contentious Cases (Hishō Jiken - 非訟事件): Courts also handle various non-contentious matters as prescribed by law, such as certain family law procedures (e.g., declarations of disappearance, appointments of guardians) and commercial registrations.

The constitutional limits on the Diet's power to confer such non-traditional adjudicatory functions on the courts are debated. Some scholars argue that such powers must still align with the fundamental nature of the judicial function, involving a principled legal decision in a structured proceeding leading to a final resolution.

Limitations on Judicial Power (Shihōken no Genkai)

Even when a matter might appear to fit the definition of a "legal dispute," there are several recognized limitations on the exercise of judicial power. These limitations can be categorized as follows:

  1. Explicit Constitutional Limitations:
    The Constitution itself carves out specific exceptions to the courts' jurisdiction:
    • Disputes over Diet Members' Qualifications: Article 55 states that "Each House shall judge disputes related to qualifications of its members." This is an internal matter for each House of the Diet.
    • Impeachment of Judges: Article 64 provides for the Diet to set up an impeachment court to try judges against whom removal proceedings have been instituted.
  2. Limitations under International Law:
    Established principles of international law impose certain restrictions:
    • Diplomatic Immunity: Foreign diplomats and their families generally enjoy immunity from the jurisdiction of Japanese courts.
    • State Immunity (Sovereign Immunity): Historically, foreign states enjoyed absolute immunity. However, modern international law, and Japanese practice following a Supreme Court judgment (July 21, 2006 [Heisei 18]) and the subsequent enactment of the Act on the Civil Jurisdiction of Japan with respect to a Foreign State, has moved towards a doctrine of restrictive immunity. This doctrine distinguishes between a foreign state's sovereign acts (jure imperii), which generally remain immune, and its commercial or private law acts (jure gestionis), for which immunity may not apply.
  3. Limitations Derived from Constitutional Interpretation (Separation of Powers, Self-Restraint):
    These are perhaps the most complex and debated limitations, often arising from the judiciary's understanding of its role within the broader constitutional structure and its relationship with the political branches.
    • Internal Autonomy of Other Branches (Jiritsuken - 自律権):
      Courts generally exercise self-restraint and refrain from intervening in the purely internal procedures and autonomous decisions of the legislative and executive branches, provided these do not directly infringe upon legally protected individual rights or violate clear constitutional mandates. For example, the Supreme Court, in the Police Law Amendment Case (Grand Bench judgment, March 7, 1962 [Shōwa 37]), declined to rule on the validity of Diet proceedings concerning the extension of a session, citing respect for the Diet's autonomy.
    • The "Act of State" or "Political Question" Doctrine (Tōchi Kōi Ron - 統治行為論):
      This highly significant, though controversial, doctrine holds that certain governmental acts, by their very nature, are so highly political and involve such fundamental decisions of national policy that they are considered non-justiciable, i.e., unsuitable for judicial review, even if they might theoretically present a "legal dispute." The resolution of such matters is deemed best left to the political judgment of the elected branches (the Diet and the Cabinet) and, ultimately, to the electorate.
      • The Sunakawa Case (Supreme Court, Grand Bench, December 16, 1959) is a leading example. The Court stated that the U.S.-Japan Security Treaty, being a matter of high national policy with profound implications for Japan's existence, was primarily a matter for political judgment and outside judicial review unless it was "clearly and obviously unconstitutional and void."
      • Similarly, in Tomabechi v. Japan (Supreme Court, Grand Bench, June 8, 1960 [Shōwa 35]), the Court held that the dissolution of the House of Representatives by the Cabinet was a highly political "act of state" not amenable to judicial scrutiny.
        The scope and legitimacy of the tōchi kōi doctrine remain subjects of intense academic debate. While courts have occasionally invoked it, many scholars argue for its extremely restrictive application, concerned that it could be used to shield unconstitutional government actions from judicial oversight. The modern trend in scholarship leans towards analyzing such issues through the lens of functional role-sharing and appropriate deference to political branches on policy matters, rather than declaring entire categories of governmental action as absolutely non-justiciable.
    • Internal Matters of Autonomous Organizations / "Partial Societies" (Bubun Shakai - 部分社会):
      Courts have sometimes shown reluctance to intervene in disputes that are considered purely internal to certain autonomous private or public organizations, such as political parties, universities, local assemblies (for certain disciplinary matters), and religious bodies. This approach, sometimes referred to as the "partial society" theory, suggests that such organizations have their own internal norms and dispute resolution mechanisms, and judicial intervention should be limited unless the dispute directly implicates fundamental legal rights cognizable by the general legal order or if the organization's internal processes are manifestly unfair or contrary to public policy.
      • For local assemblies, the Supreme Court in the Yamakita Village Assembly Member Suspension Case (Grand Bench judgment, October 19, 1960 [Shōwa 35]) declined to review a council member's temporary suspension, viewing it as an internal disciplinary matter. However, if a disciplinary action leads to expulsion or significant financial detriment, courts may be more willing to intervene.
      • Regarding universities, in the Toyama University Unit Accreditation Case (Grand Bench judgment, March 15, 1977 [Shōwa 52]), the Court held that academic matters like the conferral of credits are generally internal university affairs subject to its autonomous judgment, unless "special circumstances" exist that directly connect the issue to rights under general civil law.
      • For political parties, in the Communist Party Hakamada Case (Grand Bench judgment, December 20, 1988 [Shōwa 63]), the Court respected party autonomy in disciplinary matters concerning a member's expulsion, intervening only if the party's rules or procedures were grossly unfair or violated public order, or if the expulsion directly affected the member's non-party legal rights.
      • Religious organizations present a particularly complex area. Courts will generally avoid interpreting religious doctrine or determining the validity of religious leadership claims as such. The Itamandala Case (Supreme Court, Grand Bench, April 7, 1981 [Shōwa 56]), involving a dispute over the authenticity of a sacred object, exemplifies this, as the Court found the matter non-justiciable because it required a determination of religious tenets. Similarly, in the Rengeji Temple Case (Supreme Court, First Petty Bench, September 8, 1989 [Heisei 1]), where a doctrinal schism led to disputes over temple control, the Court was reluctant to intervene in what it perceived as an essentially religious dispute. However, courts may adjudicate property disputes or secular legal positions (like the directorship of a religious corporation) even if they arise from an internal religious conflict, provided the resolution does not necessitate delving into purely doctrinal matters.

Conclusion: A Broad Mandate Tempered by Principled Limitations

The judicial power vested in the Japanese courts under the Constitution is extensive, encompassing the authority to resolve "all legal disputes," a term that has been interpreted to cover a wide range of civil, criminal, and administrative controversies. This broad mandate is essential for upholding the rule of law, protecting individual rights, and ensuring the accountability of other governmental branches.

However, this power is not without its boundaries. Explicit constitutional carve-outs, principles of international law, and, most significantly, doctrines of judicial self-restraint derived from the separation of powers and the nature of certain governmental actions (like "acts of state" or internal matters of autonomous bodies) define the limits of justiciability. The precise contours of these limitations, particularly those that are not textually explicit, continue to be shaped by judicial precedent and scholarly debate, reflecting an ongoing effort to balance the judiciary's crucial role in a constitutional democracy with due respect for the functions of other branches and the autonomy of various societal spheres.