Chronology 1957 - 1966
March 8 - PM Kishi Nobusuke, at a meeting of the Budget Council for the House of Representatives, defends the statement that the Emperor continues to be the current Head of State (Tennō wa genzai mo Genshu de aru天皇は現在でも元首である).
April 8 - The Union of Councilors for the Formation of an Autonomous Constitution (Jishu Kenpō Kisei Giin Dōmei i自主憲法規制議員同盟) publishes the Hirose Test Plan for Japanese Constitutional Revision (Nihon Koku kenpō kaisei Hirose shian日本国憲法改正広瀬試案).
August 13-14 - The LDP Constitutional Research Group holds its first general meeting. Takayanagi Kenzō 高柳賢三 is elected President. (On 9.21, the Socialist Party's application to join the Group is refused.)
June 8 - Miyazawa Toshiyoshi 宮沢俊義 et al. inaugurate the Constitutional Problems Research Group (Kenpō Mondai Kenkyūkai 憲法問題研究会).
March 30 - The Tokyo District Court rules that the American occupation forces in the Sunakawa Case contravene the banning of military power as expressed in article 9.
December 16 - In the Sunakawa Case, the Supreme Court avoids passing judgment on the constitution's relation to the Security Agreement.
January 19 - Treaty of Mutual Cooperation and Security between Japan and the United States of America (Nichibei Anzen Hoshō Jōyaku 日米安全保障条約) signed.
May 3 - The Constitutional Problems Research Group (Kenpō Mondai Kenkyūkai 憲法問題研究会) announces that they "hold many doubts on the basic points" (kihonteki na ten ni tsuite, sukunaranu gimon o idaku 基本的な点について、少ならぬ疑問を抱く) of the revised U.S.-Japan Security Treaty.
Katayama Tetsu 片山哲 et al., after leaving the Union for Defense of the Constitution (Goken Rengō 護憲連合), form the New Citizens' Congress for Constitutional Defense (Kenpō Yōgo Shin Kokumin Kaigi 憲法擁護新国民会議) with members of the Citizens' Society Group and National Workers Group (minsha-zenrō kei 民社全労系).
May 19 - The LDP, at a session of the House of Representatives, passes in separate ratifications the Revised Agreement on the U.S.-Japan Security Treaty and the U.S.-Japan Status of Forces Agreement (Nichibei Chii Kyōtei 日米地位協定). These are concluded on 6.19 without the substantive deliberation in the House of Councillors; effective 6.23)
September 22 - The Socialist Party Constitutional Research Group (Kenpō Chōsa Kai 憲法調査会) publishes its "On the Recent Trends of the LDP Constitutional Research Group" (Kenpō Chōsa Kai no saikin no dōkō ni tsuite 憲法調査会の最近の動向について), which holds that the LDP Constitutional Research Group aims to corrupt the Constitution.
October 4 - The LDP Constitutional Research Group begins concrete deliberation on the pros and cons of constitutional revision.
February 1 - The Budget Committee of the House of Representatives holds a debate over which body has the authority to draft proposals concerning constitutional revision.
May 30 - The Society of Christians Protecting the Constitution (Kenpō o Mamoru Kirisuto-sha no Kai 憲法を守るキリスト者の会) is formed.
June 19 - Takayanagi Kenzō, president of the LDP Constitutional Research Group, submits a report to the Group General Assembly holding that constitutional revision is unnecessary.
September 4 - Within the LDP Constitutional Research Group, a statement tabled by 18 members is submitted, "The Direction of Constitutional Revision" (Kenpō Kaisei no Hōkō 憲法改正の方向).
February 28 - Nakasone Yasuhiro et al. issue a statement agreeing with the conclusion of a report by the LDP Constitutional Research Group Subcommittee holding that the constitution did not come from the free will of Japan's citizens (kenpō seitei wa kokumin no jiyū ishi ni wa yoranai 憲法制定は国民の自由意志には寄らない).
March 5 - PM Ikeda Hayato 池田勇人 announces at a meeting of the Budget Council of the House of Representatives that the cabinet also has the right to make proposals concerning constitutional revision.
May 3 - The Constitutional Problems Research Group (Kenpō Mondai Kenkyūkai 憲法問題研究会) and the LDP Constitutional Research Group announce their opposition to constitutional revision.
July 3 - The LDP Constitutional Research Group submits its final report.
November 19 - The Union for Defense of the Constitution (Goken Rengō 護憲連合) hosts a citizens' convention against constitutional revision (kenpō kaiaku hantai no kokumin taikai 憲法改悪反対の国民会議).
March 6 - The Liaison Congress of Groups for the Prevention of Constitutional Revision (Kenpō Kaiaku Soshi Kakukai Renraku Kaigi 憲法改悪阻止各会連絡会議; otherwise known as the Kenpō Kaigi 憲法会議) is formed.
April 25 - The National Constitutional Research Group (Zenkoku Kenpō Kenkyūkai 全国憲法研究会; otherwise known as Zenkokuken 全国憲) is inaugurated.
March 4 - Minister of Foreign Affairs Shiina Etsusaburō 椎名悦三郎 and Defense Agency Director-General Matsuno Raizō 松野頼三, in a meeting of the Budget Council of the House of Representatives, announce the unified government view that the overseas dispatch (kaigai hahei 海外派兵) of the SDF for any reason is a violation of the constitution. The next day, however, Minister Shiina states that the dispatch of troops (hahei 派兵) is premised on the exercise of military force and that deployment (haken 派遣) does not fall under this definition, thus implying that this pertains to the overseas deployment of the SDF.