Post-War Legal Reforms in Japan (1945–present)

Introduction

The post-war period represents the second great transformation of the Japanese legal system. The Allied Occupation (1945–1952) dismantled the authoritarian features of the Meiji system and established a democratic, rights-based legal order. The subsequent seventy-five years have seen continued adaptation to economic change, social transformation, and international integration.

The Allied Occupation (1945–1952)

The Occupation, under GHQ/SCAP and General MacArthur, pursued democratization, demilitarization, and decentralization through legal reform.

The Constitution of Japan (1946). The centerpiece of Occupation reforms, discussed separately in this series, replaced the Meiji Constitution with popular sovereignty, fundamental human rights, pacifism, and a parliamentary cabinet system.

Court System Reform. The Court Act (1947) abolished the prewar administrative court and established a unified judiciary under the Supreme Court, with judicial review power (Article 81) and judicial administration transferred from the Ministry of Justice to the Supreme Court.

Prosecutor System Reform. The Public Prosecutors Office Act (1947) established a unified prosecutorial system independent of the judiciary, with broad discretion over charging decisions.

Bar Reform. The Attorney Act (1949) established an independent bar with mandatory membership in the Japan Federation of Bar Associations (Nichibenren).

Family Law Reform. The Civil Code was amended in 1947 to abolish the patriarchal household system (ie seido), establish spousal equality, and reform inheritance, conforming to Articles 14 and 24 of the Constitution.

The 1960s: Environmental Law

Rapid economic growth created significant environmental problems. The “Big Four” pollution cases — Niigata Minamata disease, Kumamoto Minamata disease, Yokkaichi asthma, and Itai-itai disease — established precedents in tort law including joint and several liability and shifted burdens of proof. This prompted the Basic Law for Environmental Pollution Control (1967) and Japan’s sophisticated environmental regulatory system.

The Heisei Judicial Reform (1996–2006)

The Judicial Reform Council (1999–2001) led to comprehensive institutional changes.

Graduate Law Schools. American-style graduate law schools (hōka daigakuin) were established in 2004, creating a new pathway to the legal profession and aiming to increase the number of legal professionals.

The Lay Judge System. The Lay Judge Act (2004, effective 2009) introduced the Saiban-in Seido: six lay citizens sit with three professional judges to decide serious criminal cases.

Expansion of the Legal Profession. The reform aimed to increase attorneys from approximately 20,000 to 50,000.

The 2005 Companies Act

The Companies Act (Kaisha Hō, 2005) comprehensively reformed corporate law, replacing Book II of the Commercial Code. Key features included the committee system (nominating, audit, and compensation committees) as an alternative to the traditional statutory auditor (kansayaku) system and the introduction of limited liability companies (Godō Kaisha).

Civil Procedure Reform (1996)

The Code of Civil Procedure (1996) expanded discovery mechanisms, strengthened judicial case management, and introduced provisions for consolidation of related claims.

Administrative Law Reforms

The Administrative Case Litigation Act was revised in 2004 to expand standing, broaden provisional remedies, and clarify the scope of judicial review.

21st Century Criminal Justice Reform

The 2016 amendments introduced a plea-bargaining system (kōhō kōhan seido), allowing prosecutors to offer leniency in exchange for cooperation in investigating serious offenses — controversial for its potential impact on the privilege against self-incrimination. The 2023 amendments reformed sexual offense law, redefining rape as non-consensual sexual intercourse (fudōi seikō), expanding statutes of limitation, and increasing penalties.

Ongoing Legal Modernization

Active areas of development include data privacy (Act on the Protection of Personal Information, amended 2015, 2020), corporate governance (Corporate Governance Code, 2015, revised 2021), artificial intelligence regulation, blockchain, and climate change law.

Conclusion

The post-war transformation represents an arc from authoritarianism to democracy. The Occupation reforms established the fundamental framework, and subsequent decades have seen continuous adaptation through legislation, judicial interpretation, and administrative practice. The combination of constitutional stability (no amendments in 75 years) and legal flexibility exemplifies a distinctive Japanese approach to legal development.