Law Library Stacks

Back to Parliamentary Oversight of the Executive Branch


Japan’s Constitution provides for a parliamentary Cabinet system with two Houses. Each House has the right to investigate government-related matters and require reports from government agencies, the presence and testimony of witnesses, and  the production of records.

I. Introduction

The Diet, Japan’s Parliament, is composed of two Houses—the House of Representatives and the House of Councillors.[1] The Constitution provides for a parliamentary Cabinet system.  The  Prime Minister is chosen from among the members of the Diet by a resolution of the Diet.[2] The Prime Minister appoints the ministers of state, a majority of whom must be chosen from among the members of the Diet.[3] If the House of Representatives passes a no-confidence resolution, either the House of Representatives must be dissolved or the Cabinet must resign en masse.[4]  The Prime Minister and other ministers of state may choose to appear in either House at any time for the purpose of speaking on bills, regardless of whether they are members of the House or not. Moreover, when either House requests the presence of the Prime Minister or ministers of state at a meeting, they must appear in order to give answers or explanations.[5]

Back to Top

II. Investigations of Government-Related Matters

Each House may conduct investigations of government-related matters and require the presence and testimony of witnesses, and the production of records.[6] A House also may dispatch committee members to conduct investigations.[7] Such investigations may be conducted at plenary sessions, but are usually conducted by committees.[8]  An investigation may be initiated by the request of a committee member or decision of a committee’s board of directors.[9]  The subject matter of investigations may cover anything related to the government. As an example, the president of a private school was recently summoned to testify before the Budget Committees of both Houses in regard to a scandal surrounding the school’s acquisition of public property and connections to politicians, including Prime Minister Abe.[10]

When a House or House committee requests a report or records from the Cabinet or a government agency, the Cabinet or a government agency must submit the requested item(s).[11] If the Cabinet or agency fails or refuses to comply with the request, it must give a plausible reason.[12] If the House or committee finds the reason to be unacceptable, the House or committee may ask the Cabinet to declare that the production of the reports and records would be gravely detrimental to the national interest.[13] If the Cabinet does not make such a declaration, it must submit the requested report or records.[14]  When the head of the agency declines to provide   reports or records because they contain specially designated national secrets,[15] the requesting House or committee may request the Board of Oversight and Review of Specially Designated Secrets[16] of the House to which it belongs to examine the refusal.[17] A House or House committee may also request the Board of Audit to carry out an audit upon specified matters and to produce a report on the results.[18]

The Act on Oaths and Testimonies of Witnesses in a House has provisions to regulate the testimony of witnesses.[19] If a House requests a person to attend a meeting and testify or submit a document, the person must comply.[20] A person who does not appear, does not submit a requested document, or refuses to take an oath or testify is punishable by imprisonment for up to one year and/or a fine of up to 100,000 yen (approximately US$900).[21] A witness who makes a false statement under oath at a House meeting is punishable by imprisonment for three months to ten years.[22] A witness may be accompanied by an attorney and consult with him/her while providing testimony.[23]

In order to conduct long-term and comprehensive research relating to fundamental matters of government, the House of Councillors creates research committees.[24] Since 1986, three research committees have been established every three years.[25] The three current research committees are the Committees for International Economy and Diplomatic Relations, People’s Daily Life and Economy, and Natural Resources and Energy.

Back to Top

Recommended Sources for Further Research

The items cited in the footnotes are the most useful sources for research.

Back to Top

Prepared by Sayuri Umeda
Senior Foreign Law Specialist
August 2017

[1] CONSTITUTION OF JAPAN art. 42 (1946),

[2] Id. art. 67.

[3] Id. art. 68.

[4]  Id. art. 69.

[5] Id. art. 63.

[6]  Id. art. 62.

[7] Diet Act, Act No. 79 of 1947, amended by Act No. 86 of 2014, art. 103,

[8] 参議院のあらまし: 委員会の活動(2)国政調査 [Summary of House of Councillors: Activities of Committees (2) Investigation in Relation to the Government], HOUSE OF COUNCILLORS, (last visited Aug. 4, 2017).

[9] Id.

[10] Yoko Wakatsuki & Joshua Berlinger, Japan PM Shinzo Abe Embroiled in Land-Sale Scandal, CNN (Mar. 24, 2017),; Gov't Spokesman Rebuts Moritomo Gakuen Chief’s Abe Donation Claim, MAINICHI (Mar. 23, 2017),

[11] Diet Act art. 104, para. 1.

[12]  Id. art. 104, para. 2.

[13]  Id. art. 104, para. 3.

[14]  Id. art. 104, para. 4.

[15] Act on the Protection of Specially Designated Secrets, Act No. 108 of 2013, art. 3, para. 1.

[16] The Board of Oversight and Review of Specially Designated Secrets was established in both Houses to review the appropriateness of refusals to provide reports or records.  Diet Act art. 102-13.

[17]  Id. art. 104-2.

[18]  Id. art. 105.

[19] Act on Oaths and Testimonies of Witnesses in a House, Act No. 225 of 1947, amended by Act No. 86 of 2014, (in Japanese).

[20] Id. art. 1.

[21]  Id. art. 7.

[22]  Id. art. 6.

[23]  Id. art. 1-4.

[24] Diet Act art. 54-2.

[25] 参議院の調査会 [Research Committees of House of Councillors], HOUSE OF COUNCILLORS, (last visited Aug. 4, 2017).