Asian Parliamentary Openness Index 2026

Assessment date: October 2026

Japan

Government system: Parliamentary Cabinet system. The Cabinet is collectively responsible to the Diet; the Prime Minister is designated by the Diet from among its members.
Parliamentary type: Bicameral
Parliament name: The National Diet of Japan (Kokkai). Lower Chamber: House of Representatives (Shugiin). Upper Chamber: House of Councillors (Sangiin).
Parliament official website:

Key findings

Japan publishes plenary and committee transcripts, with meeting and speech data available through the National Diet Library's JSON/XML API. Live broadcasts and archived recordings are also available. Detailed agendas may be announced at short notice. Statutory asset and interest reports are available for in-person inspection, rather than as downloadable digital records. Information about Members' publicly funded secretaries is not proactively published online. Official records describe limited in-person disclosure arrangements introduced in 2004; these historical records alone do not establish their current operation. The Diet is not subject to Japan's national Freedom of Information Act. Each chamber operates its own administrative-document disclosure scheme. The House of Representatives excludes legislative and research documents from that scheme, while the House of Councillors excludes designated legislative and research documents. Separately, proceedings and various legislative materials are publicly available. The House of Councillors publishes individual voting records for recorded plenary votes. Most House of Representatives decisions use standing votes or acclamation, which do not provide a complete individual voting record.

Aggregated score

Across both chambers

76.12%

(43.04/56.54)

Openness on Information: 64.42% (23.54/36.54)
Openness on Accountability: 100.00% (6/6)
Openness on Citizen Participation: 96.43% (13.5/14)

Lower chamber

73.79%

(20.42/27.67)

Openness on Information: 61.79% (10.92/17.67)
Openness on Accountability: 100.00% (3/3)
Openness on Citizen Participation: 92.86% (6.5/7)

Upper chamber

78.35%

(22.62/28.87)

Openness on Information: 66.89% (12.62/18.87)
Openness on Accountability: 100.00% (3/3)
Openness on Citizen Participation: 100.00% (7/7)

Share

How a parliament proactively discloses comprehensive legislative, financial, administrative, and procedural data in accessible formats.

22 indicators

Grouped by

Not achieved (3 indicators)

All questions within the indicator receive a score of 0, excluding those that are not applicable to the country context.

Not achieved

0.00/0.50

5 countries achieved

Not achieved

0.00/0.50

5 countries achieved

Not achieved

0.00/0.50

4 countries achieved

Partly achieved (9 indicators)

The indicator receives some score, excluding those that are not applicable to the country context.

Partly achieved

0.75/1.00

6 countries achieved

Partly achieved

0.25/1.00

4 countries achieved

Partly achieved

0.50/1.00

2 countries achieved

Partly achieved

0.50/1.00

4 countries achieved

Partly achieved

0.50/1.00

1 country achieved

Partly achieved

0.50/1.00

1 country achieved

Partly achieved

0.25/1.50

0 countries achieved

Partly achieved

0.50/1.00

6 countries achieved

Partly achieved

0.50/1.00

6 countries achieved

Achieved (7 indicators)

All questions within the indicator receive a full score, excluding those that are not applicable to the country context.

Achieved

1.00/1.00

9 countries achieved

Achieved

1.00/1.00

5 countries achieved

Achieved

0.67/0.67

7 countries achieved

Achieved

1.00/1.00

4 countries achieved

Achieved

1.00/1.00

5 countries achieved

Achieved

1.00/1.00

4 countries achieved

Achieved

1.00/1.00

6 countries achieved

N/A (3 indicators)

All questions within the indicator are not applicable to the country context.

N/A

1 country achieved

N/A

6 countries achieved

N/A

4 countries achieved

About the respondent

PoliPoli

PoliPoli Inc. (Japan) — a private civic technology company operating a policy platform connecting citizens, legislators and government agencies. PoliPoli provided factual information and contextual input for the Japan section. It does not conduct parliamentary monitoring, and its contribution should not be understood as an institutional evaluation or endorsement of the Index or its findings.

Year the organization began monitoring Parliament

Not applicable

Name of respondent

Takuya Nakaizawa

Email of respondent to correspond with

[email protected]

Conduct deeper analysis

Machine-readable data for all countries in this cycle is available for download.

For academic use, please contact Professor Akihiro Ogawa (Email: [email protected] )

Download raw data

Submit your feedback

If you have concerns about a country’s score, suggestions for improving the index, or feedback on the website experience, you can submit feedback. Your input will be reviewed and shared with the team best placed to address it.