The Constitutional Revision Research Project seeks to follow, analyze, and document constitutional discussion in Japan.
Mainichi ShimbunThe Constitution of Japan (also known as the Postwar Constitution) went into effect in 1947, replacing the Meiji Constitution of 1890. It is recognized as the oldest unamended constitution in the world as of 2022, having never undergone revision in over 70 years since its promulgation. Throughout this time, constitutional revision has become an important subject of vigorous debate and discussion in Japan and around the world.*
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Emerging Political Party Releases Constitutional Draft
Sanseito (参政党) published a constitutional draft in May 2025. Founded in 2020, Sanseito is generally regarded as a right-wing populist political party. As of May 2025, it holds four seats in the Diet and is aiming to win six seats in the House of Councillors election in summer 2025, fielding candidates in all 45 electoral districts (see NHK coverage, and the English overview on its official website).
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