Constitution Memorial Day (憲法記念日 Kenpō Kinen-bi). The effective Constitution of Japan that radically changed the nature and principles of governing the state was enacted on May 3, 1947. Basic provisions of the Constitution were prepared by US lawyers from occupation forces headquarters, and though opinion of Japanese politologists and lawyers was taken into account while drawing up the text, some experts still call this Constitution "pro-American”.

Main changes affected status of the Emperor who lost his rights as the leading and governing person of the nation. Henceforth the Emperor becomes the "symbol of the state”. Article 9 declares Japan’s renunciation of war as sovereign right of the Japanese nation in settlement of international disputes and that is essential distinction of Japan from fundamental laws of other countries. There have been recognized such fundamentals like sovereignty of the Japanese nation, people’s basic rights, separation of powers and local government principles. All that has brought Japan to parliamentary democracy.