The Allied Council for Japan or ACJ was established in Tokyo to give guidance and advice to SCAP regarding the administration of the occupation of Japan. It was the FEC's outpost in Tokyo. The conference of the Foreign Ministers from the United States, the United Kingdom and the Soviet Union held inMoscow in December 1945 decided to establish the Far Eastern Commission in Washington along with the Allied Council for Japan in Tokyo. The four delegations to the Council represented the U.S., the British Commonwealth (Australia jointly representing the U.K., New Zealand and India), the Soviet Union and China. The chairman of the council was SCAP (or SCAP's representative).

While the function of the Allied Council for Japan was to advise and guide SCAP regarding the implementation of directives concerning the terms of surrender and the administration of the occupation, actually it was intended to monitor and keep an eye on SCAP. With the exception of land reform and the purge of public officials at the beginning of the occupation it had little effect. MacArthur's dislike for intervention from the Allied Powers combined with the start of the Cold War between the U.S. and the Soviet Union led to the Council's being reduced to a mere shell with virtually no functions. On April 28, 1952, the San Francisco Peace Treaty was signed, ending the mission of the Allied Council for Japan as well as the Far Eastern Commission.

The procedure to revise the Constitution, according to Article 73 of the Meiji Constitution, first required an order by the Emperor to start deliberations in the Imperial Diet on proposed amendments. In addition to this, to gain approval the amendment had to garner at least two thirds of the votes of the lawmakers present in both the House of Representatives and the House of Peers, in sessions where two thirds or more of all the lawmakers were present. In reality, the Constitution had never been amended since its enactment on November 29, 1890. Yet, the Constitution of Japan was enacted through Article 73 of the Meiji Constitution.

This was a directive issued by GHQ on October 4, 1945 abolishing the systematic repression of freedoms such as the freedom of thought and speech that the Japanese government had been systematically controlling. The memorandum was titled "Removal of Restrictions on Political, Civil, and Religious Liberties." It is also known as the "Human Rights Directive." This directive eliminated laws limiting the freedom of thought, religion, assembly and speech, removed about 4,000 people from their positions in the Ministry of Home Affairs and the Higher Secret Police, granted immediate release to political prisoners and abolished the Higher Secret Police. The Higashikuni Cabinet resigned five days after the directive was issued because they could not carry it out. Their successor, the Shidehara Cabinet, released 3,000 political prisoners based on this directive, and abolished the "Thought Control Law" along with 15 other laws and statutes.

This is the provision made in Item 2 of Article 66 in the Constitution of Japan to the effect that the Prime Minister and other Ministers of State must be "Civilians." GHQ, in accordance with strong requests from the Far Eastern Commission, gave directions to include it in the constitutional amendments during deliberations in the House of Peers. The term "Civilian" did not exist in Japanese at this time, so a new word "bunmin" was created to correspond with the term used in GHQ's amendment.

This is the private group that created the "Outline of Constitution Draft." This group was formed by Iwasaburo Takano, a statistician, on November 5, 1945. It consisted of Takano, Tsunego Baba, Kojiro Sugimori, Tatsuo Morito, Tatsuo Iwabuchi, Koshin Murobuse, and Yasuzo Suzuki. GHQ took great interest in this draft, which contained provisions for democratization and the right to life, as well as abolishment of the system of exploitive landownership, and it greatly affected the creation of the GHQ draft. Takano, unable to accept the proposal of the Constitution Investigation Association, published in a magazine his own independent draft titled "Independent Draft of the Constitution of the Republic of Japan" that abolished the Emperor system and adopted a presidential system.

The Shidehara Cabinet established this committee to study and research the reform of the Constitution. It became known as the "Matsumoto Committee" as Joji Matsumoto was its chairman. Between October 27, 1945 and February 2, 1946 the committee held seven general meetings and 15 subcommittee meetings. Initially its objective was academic research and study of the Constitution, not constitutional reform. However, in response to pressure from GHQ, the Diet and public opinion, they began work on planning a proposal for revisions to the Constitution. The committee produced the "Tentative Revision of the Constitution" also known as the Matsumoto Draft as well as two proposals: the "Gist of the Revision of the Constitution" (Proposal A) and the "Constitutional Reform Proposal" (Proposal B). Of these, the Proposal A was submitted to GHQ; however, GHQ rejected it and created its own draft, which consequently led the committee to be dissolved.

The Far Eastern Commission (FEC) was the Allied Powers' top strategic decision-making agency related to the management of the occupation of Japan. In Moscow in December 1945, a convention of Foreign Ministers from the United States, the United Kingdom and the Soviet Union decided to establish the FEC to manage the occupation of Japan. The FEC replaced the Far Eastern Advisory Commission (FEAC), and was headquartered in Washington D.C. The FEC was organized to represent 13 countries: the United States, the United Kingdom, the Soviet Union, France, India, Holland, Canada, Australia, New Zealand, and the Philippines. In November of 1949 Burma and Pakistan were added to the FEC.

Policies decided by the FEC were sent via the U.S. government as orders to the Supreme Commander for the Allied Powers. The U.S., the U.K., China, and the Soviet Union all held the power to veto decisions made in the committee. The United States also had the ability to issue directives (Interim Directive Authority) in emergency situations without waiting for the decision of the FEC. However, it was absolutely necessary to get the consent of the FEC before making any changes to the Constitution, or fundamental changes to the Japanese government's overall administrative system.

The FEC was dissolved on April 28, 1952 with the San Francisco Peace Treaty enforced.

These are the abbreviations for General Headquarters, Supreme Commander for the Allied Powers. This was the agency of occupation in Japan following the war. Douglas MacArthur, then Commander-in-Chief, U.S. Army Forces Pacific, was appointed as the Supreme Commander for the Allied Powers (SCAP) on August 14, 1945. GHQ was established in Tokyo on October 2. The occupation took the form of indirect rule in which SCAP gave orders to the Japanese government which in turn carried out these directives. After MacArthur was relieved of his command by President Truman on April 11, 1951, General Matthew B. Ridgway took over as Supreme Commander for the Allied Powers. Operations by GHQ ceased when the San Francisco Peace Treaty came into effect on April 28, 1952.

Government Section or GS was the command center at GHQ for carrying out policies to democratize Japan. Government Section was established on October 2, 1945. It played a major role in the restructuring of the post-war Japanese governmental system through the purge of public officials, revision of the Constitution, reorganization of the civil service, reform of the election process, and strengthening of local governments. Of particular importance was the work done to revise the Constitution. There were seven Committees in Government Section, one to draft the text for each chapter, such as the Legislative, Executive, and Civil Rights. There was also a Steering Committee to oversee and manage the entire organization.

Although the first chief of Government Section was Brigadier General William Crist, he returned to the U.S. about two months later. His successor was Brigadier General Courtney Whitney, who aggressively supported the policies for democratization and was often at odds with G-2, which handled intelligence and censorship. After Whitney left the service, at the same time as MacArthur, the position of Chief of GS went to Major Frank Rizzo, who had chaired the Committee that drafted the chapter on finance in the GHQ Draft. The organization of Government Section changed several times : it was reduced in scale after 1948, when the major reforms had been carried out.

The Lord Keeper of the Privy Seal, also known simply as the Lord Keeper, was an official of the Imperial Court who acted as an advisor to the Emperor. In 1885, when the Cabinet system was established, the Office of the Lord Keeper of the Privy Seal was established separately from the Cabinet in the Imperial Court. The Lord Keeper kept the "Privy Seal" (the Emperor's seal) and the "Seal of State" (the national seal). He was also in charge of administering documents related to the Court such as Imperial Rescripts and Imperial Edicts. Along with these duties, he also handled petitions brought before the Emperor from the people, and carried out the Emperor's will regarding these petitions. With the beginning of the reign of the Emperor Showa in 1925, the Lord Keeper increasingly gained power over the decisions of appointing new prime ministers, leaving the influence of the elder statesmen relatively weak. The Office of the Lord Keeper of the Privy Seal was abolished on November 24, 1945.

The Potsdam Declaration was a tripartite declaration in which the United States, the United Kingdom and China called for the "Unconditional Surrender" of Japan. It was adopted in Potsdam, Germany at a conference of General Secretary of the Soviet Union Joseph V. Stalin, Prime Minister of the United Kingdom Winston S. Churchill, and President of the United States Harry S. Truman. After getting the consent of Chiang Kai-shek, the President of the Republic of China, it was announced on July 26, 1945. The Soviet Union adopted the declaration when it committed to joining the war against Japan on August 8, 1945.

Initially the Cabinet under Kantaro Suzuki ignored the declaration, but on August 14 the Imperial Conference decided to accept it. The Potsdam Declaration had 13 articles that demanded Japan eliminate militarism, allow the Allied Powers to occupy Japan, and called for the fulfillment of the Cairo Declaration (announced on November 27, 1943, it was a declaration made by the leaders of the U.S., the U.K., and China that set out the goals of the war against Japan as well as provisions for a postwar policy). It also limited the territory controlled by Japan to its four main islands, Honshu, Hokkaido, Kyushu, and Shikoku, plus some smaller islands designated by the Allies, requested the disarmament of Japan's military, the prosecution of war criminals, and the establishment of democracy and basic human rights.

SWNCC (pronounced swink) is an abbreviation for the State-War-Navy Coordinating Committee. It was an agency of the United States that was established in December of 1944 with the aim of coordinating the postwar policies of the three following the end of the war. The committee coordinated the policies of each department, and after receiving the approval of the Joint Chiefs of Staff they became the policy of the United States government. The Subcommittee on the Far East (SFE) was formed under SWNCC to draft a plan for the occupation of Japan. Two of the major policy statements produced by SWNCC were "United States Initial Post-Surrender Policy for Japan" (SWNCC150/4) and "Reform of the Japanese Governmental System" (SWNCC228).