Buraku Kaihō Jinken Kenkyūjo | Buraku Liberation and Human Rights Research Institute
The website does not deal with constitutional revision issue per se; however, the large amount of information on the website, and the Google search engine within the website allow access to many articles related to constitutional revision.
Hōgakukan Kenpō Kenkyūjo | Japan Institute of Constitutional Law
This institute opposes revision of Article 9, popular election of the Prime Minister, structural revision of the Prefectural Governments, and the process of constitutional revision. It also opposes revising the current constitution without further discussion and understanding of its principles. The website is very large and contains an online database of numerous books and theses regarding constitutions. These sources are categorized so that browsers can reach a large number of books related to a specific subject; however, this institution only introduces basic information (name of the book, author, the year published, etc.) about the sources but not their content. The website also introduces a series of articles explaining constitution-related issues for junior and senior high school students, as well as a large amount of constitution-related movements, articles, events, court judgments, and movies.
Kokka Kihon Mondai Kekyūjo | Japan Institute for National Fundamentals
Founded in 2007, this institute has organized various events, published statements, and promoted research advocating for constitutional reform, supporting Japan's territorial rights of disputed islands, and attempting to disprove Japan’s controversial wartime crimes. As of March 2019, its Director is Sakurai Yoshiko and Vice-Director is Takubo Tadae. Sakurai is a Co-Director of a group promoting a national movement for constitutional revision, Utsukushii Nippon no Kenpo o Tsukuru Kokumin no Kai (美しい日本の憲法をつくる国民の会), which is affiliated with the largest pro-constitutional revision group, Nippon Kaigi, which Takubo leads as Chair. Their event information and statements are available on the website; here is their statement calling for constitutional revision in 2018.
Nakasone Yasuhiro Sekai Heiwa Kenkyūjyo | Nakasone Yasuhiro Peace Institute (Former: Institute for International Policy Studies)
This institute offers its original revision draft in which it defines the emperor as the chief of state; moves popular sovereignty to the first chapter; renames the SDF as a security force; and clarifies foreigners’ human rights (including the right to privacy). The revision draft also establishes more detailed restrictions on separation of religion and state; establishes articles about the family and new human rights; and enforces the independence of the two Houses. It also suggests a simplified process of constitutional revision.
Nihon Anzenhoshō Kikikanri Gakkai | Japan Society for Security and Crisis Management
Founded in 2005, this group has promoted research on security, calling for constitutional revision. As of March 2019, the Honorary Chair is Prime Minister Abe Shinzō, and the board members are composed of professors, politicians, executives of private companies and retired leaders from the police and Self Defense Forces. Articles by the members are reachable on the website.
Nihon Anzenhoshō Senryaku Kenkyūjo | Security and Strategy Research Institute of Japan
This institute is owned by National Security Research Co., Ltd. (株式会社エヌ・エス・アール), a consulting company that specializes in SDF-related research. This website provides their policy proposals and articles by research fellows. They occasionally jointly release proposals, statements and books with other SDF-affiliated groups, including Nihon Gōyū Renmei (日本郷友連盟). Here is an example of a joint publication from 2006, 「憲法改正に関する提言 国防なき憲法を改正し国軍を創設せよ！」(Japanese: Live Site) .