Constitutional Amendment in Japan

Introduction

Article 96 establishes the amendment procedure: initiation by the Diet through a two-thirds majority of all members of each House, and ratification by a majority of votes cast in a popular referendum. This procedure has made the Constitution one of the most rigid in the world. No amendment has been enacted since 1947.

The Amendment Formula

The two-thirds requirement applies to “all the members of each House,” not merely those present, making the threshold higher than a simple supermajority of voting members. The referendum requires only a majority of “votes cast,” not a majority of eligible voters — a significant point because voter turnout in referendums is typically lower than in general elections. The formula reflects the framers’ desire for broad popular consensus.

The Referendum Procedure

For decades, Article 96 lacked implementing legislation. The 2007 National Referendum Act established the procedural framework. A referendum must be held between sixty and one hundred eighty days after the Diet’s initiative. A majority of valid votes suffices for ratification. The Act addresses campaign finance, media access, and public information.

Proposals to Amend Article 96 Itself

Some, including former Prime Minister Abe Shinzō, have proposed lowering the Diet threshold to a simple majority, arguing that the two-thirds requirement gives a minority veto. Opponents counter that lowering the threshold would undermine constitutional stability. The proposal has not advanced, as it requires the same two-thirds majority and referendum approval as any other amendment — creating a circular difficulty.

Major Proposed Amendments

Article 9 Revision. The LDP’s 2012 draft proposed replacing Article 9 with provisions establishing a “National Defense Force.” The 2021 LDP draft proposed adding a paragraph recognizing the SDF while maintaining existing text.

Emergency Powers. Several proposals would authorize the Cabinet to issue orders with the force of law during national emergencies, subject to subsequent Diet approval. The LDP’s 2012 draft included such provisions; critics argue they are unnecessary and could be abused.

Fundamental Rights. Proposals include adding rights to privacy and environmental protection, and modifying the public welfare limitation to strengthen individual rights.

Family Law and the Upper House. Conservative proposals would modify Article 24 to emphasize the family as a fundamental social unit. Upper House reform proposals include merging constituencies or modifying proportional representation.

Political and Social Barriers to Amendment

Public Attachment. Opinion polls show a majority of Japanese regard the Constitution positively and are wary of amendment, particularly of Article 9.

The Two-Thirds Requirement. No governing coalition has consistently commanded two-thirds majorities sufficient to initiate amendment.

Referendum Uncertainty. No constitutional referendum has ever been held, and the outcome of a first referendum is unpredictable.

Political Polarization. The LDP and Komeito have different priorities; opposition parties oppose amendment, particularly of Article 9.

The Cabinet Legislation Bureau. The Bureau’s tradition of flexible constitutional interpretation has reduced pressure for formal amendment. When the government can achieve objectives through reinterpretation — as with the 2014 collective self-defense decision — the political impetus for amendment diminishes.

Constitutional Revision versus Interpretation

The distinction between formal amendment and interpretive change is a central feature of Japanese constitutional politics. The meaning of “war potential” (Article 9), the “public welfare” limitation (Article 13), and “cruel punishments” (Article 36) have all evolved through interpretation rather than amendment.

Conclusion

Article 96 has functioned as an effective lock on constitutional change for over seventy-five years. Whether this rigidity is a strength — protecting the Constitution from transient political pressures — or a weakness — preventing necessary adaptation — depends on one’s assessment of the desirability of constitutional change. The debate over amendment reflects deeper questions about the nature of the Constitution itself.