The State Council was created under the Constitution of 1921 as a replacement for both the upper house of Imperial Diet, House of Peers, and the Privy Council of Japan. Like its predecessors, the State Council is mainly an advisory body to the Government. However, the Council is more representative politically and socially than the National Congress. Arrangements are usually occurred during the elections in order one of two regional representatives can represent an "allied party or organization" within the National Front. Currently, there are only 65 representatives of the Nationalist Party out of 286 State Councillors.
According to the 1947 Supplementary to the Constitution Regarding the Composition of State Council, the State Council consists of members elected by three types of constituencies:
- Members elected by the members of prefectural congresses with each prefecture is represented by two deputies. Since 1947, the fixed number of regional representatives is 116 members.
- Members elected by the corporate and special interest groups which formed the "functional constituencies", including the agricultural constituencies, labour constituencies, commercial constituencies, educational constituencies, cultural constituencies and medical constituencies. Since 1966, the fixed number of functional representatives is 120 members.
- Members elected by the designated indigenous minorities of Japan, such as from Karafuto and Taiwan, which formed the "indigenous constituencies". Since 1998, the fixed number of indigenous representatives is 50 members.
Members of various sectors of Japanese society are represented in the State Council. Several famous figures like celebrities, activists, religious leaders, athletes, writers or scientists are known to ever become the members of State Council. Comedians like Enomoto Kenichi, Furukawa Roppa, Ikariya Chosuke and Tamori had served in the body, while others such Akashiya Sanma and Shofukutei Tsurube II currently serving. Former television personality and later Taiwanese cultural activist, Renho, serves as a deputy for Taihoku since 2006 and is nicknamed by the media as the "Queen of State Council" for her significant presence in the body.
Since the post of President of the Republic and of Ministers of State requires the person who also serves as the member of Congress according to the Constitution, that is impossible for the members of State Council to serve as the part of executive branch of government during its term of office.
The State Council's main function is to advise the Government of Japan (President and the Council of Ministers) on matters of grave importance including:
- proposed amendments to the Constitution of the Republic
- matters of constitutional interpretation, proposed laws, and ordinances
- proclamations of martial law
- declaration of war and termination of war
- treaties and other international agreements
- matters submitted by the Congress
- matters of general state policies.
However, the State Council rarely use its functions alone today since most of its functions are executed through the Kyogi Sokai.
The State Council has several legislative powers when the Council assembling the Kyogi Sokai with the Legislative Council. This powers are described in the 1947 Supplementary to the Constitution Regarding the Functions and Powers of State Council and the 1948 Supplementary Regarding the Consultative Meeting of State Council and Legislative Council. According to the 1947 Supplementary, the State Council can openly debated about the any legislation proposals from the Legislative Council which will be submitted to the National Congress. Furthermore, according to the 1948 Supplementary, if the three-fourth quorum is able to be achieved from among all State Councillors, the State Council can vetoes any Legislative Council’s proposal.