Glossary of Japanese Constitutional Law Terms

Introduction

Japanese constitutional law draws on a distinctive vocabulary rooted in Sino-Japanese compounds. The glossary below defines the core terms necessary for navigating the Constitution of Japan (Nihon-koku Kenpō, 1946) and the scholarly discourse surrounding it.

Kenpō (憲法)

The term Kenpō denotes “constitution” in the sense of a supreme body of fundamental law. It is compounded from ken (law/rule) and hō/pō (method/standard). In contemporary usage, Kenpō refers primarily to the Constitution of Japan, enacted on 3 November 1946 and effective on 3 May 1947. The term is also used in compound forms such as Kenpō Kaisei (constitutional amendment) and Kenpō Saiban (constitutional adjudication).

Meiji Kenpō (明治憲法)

The Meiji Kenpō, formally the Constitution of the Empire of Japan (Dai-Nihon Teikoku Kenpō), was promulgated on 11 February 1889 and took effect on 29 November 1890. It established a constitutional monarchy on the Prussian model, vesting sovereignty in the Emperor (Tennō) and granting the Diet limited legislative powers. The Meiji Constitution remained in force until its replacement by the post-war Constitution on 3 May 1947.

Kenpō Kaisei (憲法改正)

Kenpō Kaisei refers to the constitutional amendment process. Under Article 96 of the Constitution, an amendment requires the concurrence of at least two-thirds of all members of each House of the Diet, followed by ratification by a majority of votes cast in a popular referendum. No amendment has yet been adopted under this procedure.

Kenpō Saiban (憲法裁判)

Kenpō Saiban denotes constitutional adjudication, the exercise of judicial review over legislation and governmental action. Article 81 of the Constitution designates the Supreme Court as “the court of last resort with power to determine the constitutionality of any law, order, regulation or official act.”

Kihonteki Jinken (基本的人権)

Kihonteki Jinken — fundamental human rights — are enshrined in Articles 10 through 40 of the Constitution. These include both classical liberal rights (freedom of speech, assembly, and religion) and social rights (the right to maintain minimum standards of wholesome and cultured living under Article 25). The term reflects the post-war commitment to popular sovereignty and the rejection of the Meiji-era kokutai (national polity) doctrine.

Kōkyōteki Fukushi (公共の福祉)

Kōkyōteki Fukushi — the “public welfare” — is the constitutional limitation on rights. Article 12 of the Constitution provides that the people shall refrain from any abuse of their freedoms and rights and shall be responsible for utilising them for the public welfare. Article 13 likewise subjects rights to limitations in the name of the public welfare. The Supreme Court has interpreted this clause broadly, adopting a “balancing” approach that weighs the nature of the right against the governmental interest.

San-Ken Bumritsu (三権分立)

San-Ken Bumritsu — the separation of powers — divides the state’s functions among the Diet (Kokkai, legislative), the Cabinet (Naikaku, executive), and the Supreme Court (Saikō Saibansho, judicial). Articles 41, 65, and 76 of the Constitution respectively vest each branch with its primary function, though the system incorporates checks and balances, including the Diet’s designation of the Prime Minister and the Supreme Court’s power of judicial review.

Kokkai (国会)

Kokkai — the National Diet — is “the highest organ of state power” (Article 41) and “the sole law-making organ of the State” (Article 41). It consists of two houses: the House of Representatives (Shūgiin, 465 members, four-year term, subject to dissolution) and the House of Councillors (Sangiin, 248 members, six-year term, half elected every three years).

Naikaku (内閣)

Naikaku — the Cabinet — comprises the Prime Minister and other Ministers of State, as provided in Article 66. The Cabinet exercises executive power and is collectively responsible to the Diet. The Prime Minister is designated by the Diet and appointed by the Emperor; the Prime Minister appoints a majority of ministers from among Diet members.

Saikō Saibansho (最高裁判所)

Saikō Saibansho — the Supreme Court — is the court of last resort, composed of a Chief Justice and fourteen Justices (Article 79). It sits in the Grand Bench (Daihōtei, fifteen justices) for constitutional cases and in three Petty Benches (Shōhōtei, five justices each) for ordinary appeals.

Jieitai (自衛隊)

Jieitai — the Self-Defense Forces — is the de facto military force established under the Self-Defense Forces Act of 1954. Article 9 of the Constitution renounces war and prohibits the maintenance of “war potential,” but the government has long interpreted Article 9 as not denying Japan the inherent right of self-defence. The constitutionality of the Jieitai has been confirmed by the Supreme Court in Sunagawa Jiken (1959) and Eniwa Jiken (1979).

Shuken (主権)

Shuken — sovereignty — resides in the people under Article 1 of the Constitution, which declares that the Emperor derives his position “from the will of the people with whom resides sovereign power.” This marked a decisive break from the Meiji Constitution, which vested sovereignty in the Emperor.

Tennō (天皇)

Tennō — the Emperor — is “the symbol of the State and of the unity of the people” (Article 1). His functions are purely ceremonial and are subject to the approval of the Cabinet. The Emperor performs acts of state enumerated in Article 7, such as the appointment of the Prime Minister and the Chief Justice of the Supreme Court.

Dai-9-jō (第九条)

Dai-9-jō — Article 9 — is the pacifist clause. It renounces war as a sovereign right and declares that “land, sea, and air forces, as well as other war potential, will never be maintained.” The government’s interpretation treats the Jieitai as not constituting “war potential” but rather as the minimum force necessary for self-defence.

Kenpō Dai-96-jō (憲法第九十六条)

Kenpō Dai-96-jō — Article 96 — governs constitutional amendments. It requires a two-thirds majority in each House of the Diet and a majority of votes cast in a popular referendum. The Diet established the enabling legislation for referenda in 2007 (Act on Procedures for Amendment of the Constitution of Japan).

Kenpō Dai-81-jō (憲法第八十一条)

Kenpō Dai-81-jō — Article 81 — confers the power of constitutional review on the Supreme Court, providing that it is “the court of last resort with power to determine the constitutionality of any law, order, regulation or official act.” The Supreme Court has exercised this power with restraint, invalidating legislation in only a handful of cases.

Jinken (人権)

Jinken — human rights — encompasses the catalogue of rights in Articles 10–40 of the Constitution. The term is synonymous with Kihonteki Jinken in most contexts. The constitutional human rights provisions apply vertically (state–individual), and the Supreme Court has extended their application to private disputes through the “indirect application” doctrine (kan setsu teki yōyō).

Byōdō (平等)

Byōdō — equality — is guaranteed by Article 14(1), which provides that “all of the people are equal under the law and there shall be no discrimination in political, economic or social relations because of race, creed, sex, social status or family origin.” The Supreme Court has read Article 14 flexibly, permitting reasonable classifications that satisfy a rational-basis or strict-scrutiny standard depending on the nature of the classification.

Jiyū (自由)

Jiyū — freedom — appears in multiple constitutional provisions, including the freedoms of thought (Article 19), conscience (Article 19), religion (Article 20), assembly and association (Article 21), speech and the press (Article 21), academic freedom (Article 23), and choice of occupation (Article 22).

Minshu-shugi (民主主義)

Minshu-shugi — democracy — is a foundational principle of the post-war Constitution. It manifests in popular sovereignty, universal suffrage, the Diet’s status as the highest organ of state power, and local self-government (Article 92).