Japan Constitution Day (Kenpo Kinenbi) - May 3, the 1947 Constitution
Japan's Constitution Memorial Day (Kenpo Kinenbi) on May 3 marks the 1947 entry into force of the postwar Constitution. Drafted under Allied occupation, the document enshrined Article 9 pacifism, fundamental human rights, and popular sovereignty, and the holiday is the second day of Golden Week.
Next observed in JP - 憲法記念日
Federal holidayPublished October 15, 2026
- Observed in
- Where observed
- When
- May
- Frequency
- Same date every year
- Days off
- 1 day - federal workers / banks off
- Public status
- Federal / public holiday (banks + federal offices closed)
Japan's Constitution Memorial Day (Kenpo Kinenbi) on May 3 marks the 1947 entry into force of the postwar Constitution. Drafted under Allied occupation, the document enshrined Article 9 pacifism, fundamental human rights, and popular sovereignty, and the holiday is the second day of Golden Week.
The one-line summary
National public holiday on May 3, observed every year. Marks the 1947 entry into force of the postwar Constitution of Japan. Federal category, standard tier.
Origin
The Constitution of Japan was drafted in February 1946 by the Government Section of the Supreme Commander for the Allied Powers (GHQ/SCAP), the occupation authority under General Douglas MacArthur. The Japanese government had begun drafting revisions to the 1889 Meiji Constitution in late 1945, but the GHQ draft replaced those efforts and was largely retained as the final text.
The new Constitution was promulgated on November 3, 1946 - the birthday of Emperor Meiji - and entered into force on May 3, 1947. May 3 was chosen because it fell six months after promulgation and because the Allied occupation authorities preferred to avoid scheduling such a fundamental constitutional moment on a date with heavy imperial symbolism.
The document defined Japan as a constitutional monarchy with popular sovereignty. Article 1 declared the Emperor to be the symbol of the state and of the unity of the people, deriving his position from the will of the people. Article 9 renounced war and the maintenance of war potential. Articles 11 to 40 set out fundamental human rights, including equality before the law, freedom of speech, and academic freedom.
When it falls
May 3, every year. Kenpo Kinenbi is a fixed Gregorian date and does not move. The day is the second of the four Golden Week holidays, falling between Showa Day on April 29 and Children's Day on May 5. When May 3 falls on a Sunday, the substitute-holiday rule transfers the observed day to Monday May 4.
How it is observed
The National Diet Building in Nagatacho, Tokyo, is opened to the public on Constitution Memorial Day, with guided tours and exhibits on the legislative process. Civic groups and universities host public lectures on the Constitution, particularly on the anniversary of major amendments and on debates over Article 9. Schools often hold assemblies that explain the Constitution to younger students.
Editorial pages and political commentators use the day to revisit debates on constitutional revision. Protest marches around the National Diet Building are common, both in support of and against revision of Article 9. Some local governments hold readings of the Constitution at public halls.
Legal status
Kenpo Kinenbi on May 3 is a national public holiday under the Holidays Act of 1948. Government offices, banks, and most businesses close. The Constitution itself is the supreme law of Japan; the procedure for amendment is set out in Article 96, which requires a two-thirds vote in each house of the Diet followed by a popular referendum.
Golden Week context
Constitution Memorial Day is the second day of Golden Week, the four-holiday cluster that runs from April 29 through May 5. The cluster includes Showa Day (April 29), Constitution Memorial Day (May 3), Greenery Day (May 4), and Children's Day (May 5). When sandwiched weekends fall on either side of the cluster, the result is a 7-day continuous break.
Golden Week is one of the busiest domestic travel periods in Japan. Domestic rail ridership, air travel, and expressway traffic all peak during the cluster, and tourism operators treat the period as the spring high season. The Cabinet Office's holiday schedule treats the four days as a single travel window for forecasting purposes.
Contested debates
Article 9 has been the subject of recurrent political debate since the 1950s. The article renounces war and the threat or use of force as a means of settling international disputes, and forbids the maintenance of land, sea, and air forces as well as other war potential. The Self-Defense Forces, established in 1954, have been ruled by successive cabinets not to violate Article 9, though critics argue the constitutional fit has always been strained.
Prime ministers from Junichiro Koizumi to Shinzo Abe have pushed for formal recognition of the Self-Defense Forces in the Constitution or for an explicit right of collective self-defense. Public opinion polls consistently show majority support for retaining Article 9, though support for adding a self-defense clause has grown in some surveys. Any amendment requires a two-thirds majority in each house of the Diet followed by a popular referendum, a threshold that has not been met.
The Constitution by the numbers
The three principles
The Constitution is built around three core principles articulated in the preamble and early articles: popular sovereignty, pacifism, and fundamental human rights. Popular sovereignty, declared in the preamble, holds that sovereignty resides in the people. Pacifism, set out in Article 9, renounces war and the maintenance of war potential. Fundamental human rights, articulated in Articles 11 to 40, guarantee civil and political rights that the state is obliged to uphold.
These three principles replaced the earlier Meiji framework, in which sovereignty resided in the Emperor and rights were concessions of the state rather than entitlements of the people. The shift was the most significant constitutional change in modern Japanese history.
Constitution and the Diet
The Constitution grants the National Diet, Japan's bicameral legislature, broad lawmaking authority. The House of Representatives and the House of Councillors each have powers defined by the Constitution, with the lower house able to prevail in budget disputes and on the prime minister's choice. The Constitution also defines the role of the Cabinet, the Prime Minister, and the courts.
Constitutional revision would require a two-thirds vote in each house of the Diet followed by a majority in a popular referendum. Since 1947, several amendment proposals have been introduced, but none has cleared the two-thirds threshold in both houses. The 2007 Act on Procedures for Amending the Constitution established detailed referendum procedures.
Related Japanese holidays
Constitution Memorial Day is the central day of Golden Week. The four-holiday cluster includes Showa Day (April 29), Constitution Memorial Day (May 3), Greenery Day (May 4), and Children's Day (May 5). Greenery Day was created in 1989 when the Emperor's Birthday was renamed Showa Day, and the May 4 date was chosen to fill the gap and link to nature themes.
Sources
- Cabinet Office of Japan - National Holidays (official list and history of national public holidays).
- House of Representatives of Japan - The Constitution of Japan (full English text of the Constitution, including Article 9).
- Encyclopaedia Britannica - Constitution of Japan (historical and analytical overview of the 1947 Constitution).
- Nippon.com - Constitution Memorial Day and Article 9 (editorial coverage of the holiday and ongoing debates).