Constitutional Supremacy and Judicial Review in Japan

Introduction

The Constitution of Japan establishes constitutional supremacy (Article 98) and judicial review (Article 81), creating a system in which the Constitution is the supreme legal norm and courts possess authority to determine the constitutionality of laws and official acts. The operation of these principles has generated extensive scholarly debate.

Constitutional Supremacy: Article 98

Article 98(1) provides: “This Constitution shall be the supreme law of the nation and no law, ordinance, imperial rescript or other act of government, or part thereof, contrary to the provisions hereof, shall have legal force or validity.” The supremacy clause establishes a hierarchy: the Constitution at the apex, followed by treaties and international law, then statutes and domestic instruments. Article 98(2) further requires Japan to faithfully observe treaties and the established law of nations. The provision extends to “any act of government,” ensuring no authority is exempt from constitutional constraints.

Judicial Review: Article 81

Article 81 provides: “The Supreme Court is the court of last resort with power to determine the constitutionality of any law, order, regulation or official act.” The prevailing interpretation — accepted by the majority of scholars — is that all courts exercise judicial review incident to their jurisdiction over concrete cases. In K.K. Serin v. Japan (1952), the Court held that lower courts possess this authority, with the Supreme Court as final arbiter. This “incidental review” model follows the American tradition: courts do not issue abstract advisory opinions but determine constitutional questions only as necessary to resolve actual disputes.

Abstract versus Concrete Review

Japanese courts may exercise only concrete review. In Japan v. K. (1954), the Court declined to rule on constitutionality in the absence of a specific dispute. Some scholars argue that Article 81’s text — conferring power to determine constitutionality of “any law” — does not limit review to concrete cases, but the dominant view aligns with judicial restraint and separation of powers.

The Political Question Doctrine

In the Sunagawa Case (Supreme Court, Grand Bench, 1959), the Court held that the US-Japan Security Treaty presented a political question (seijiteki mondai) not suitable for review unless “clearly unconstitutional or invalid.” The doctrine requires a showing that the matter is “of a highly political nature” and that the court lacks “appropriate criteria for judicial determination.” It has been applied primarily to foreign affairs and treaty matters.

The Legislative Discretion Doctrine

In economic and social welfare regulation, the Court applies legislative discretion (rippō no sairyō), upholding legislation unless “extremely unreasonable” and “clearly beyond the scope of legislative discretion.” In Matsushita v. Japan (1963), the Court upheld criminal defamation provisions as within legislative discretion. This deferential standard has resulted in most economic and social welfare legislation surviving constitutional challenge.

The Double Standard Theory

Japanese courts have adopted the double standard theory, derived from American constitutional law: restrictions on fundamental civil liberties warrant strict scrutiny requiring a compelling governmental interest, while economic regulations receive only rational basis review. The theory was explicitly adopted in K.K. Sumitomo v. Governor of Tokyo (1964). The Court has not, however, articulated a clear tiered structure comparable to US law.

The Grand Bench

Constitutional questions must be decided by the Grand Bench (daihōtei), composed of all fifteen Justices. A quorum of nine is required, and dissenting opinions are permitted and regularly published. The frequency of dissents has increased since the 1970s, reflecting greater judicial individualism.

The “Passive Judiciary” Debate

The Supreme Court has declared legislation unconstitutional only eleven times since 1947, most involving criminal procedure. Explanations include the Cabinet’s influence over judicial appointments through the Supreme Court’s Administrative Bureau, the norm of judicial consensus, deference to the Diet, and limited standing rules. Lower courts have been more willing to declare legislation unconstitutional, but such decisions are invariably reversed. The Naganuma Nike Missile Case (Sapporo District Court, 1973) — which found the SDF unconstitutional — was reversed by the Sapporo High Court in 1976 and dismissed on standing grounds by the Supreme Court in 1982.

Conclusion

Japanese judicial review is characterized by doctrinal sophistication but institutional restraint, producing a body of constitutional law that respects legislative primacy while maintaining the theoretical possibility of robust constitutional enforcement. The tension between the text of Articles 81 and 98 and the practice of judicial deference remains the central question in Japanese constitutional law.