Japan Institute for National Fundamentals
Kokka Kihon Mondai Kekyūjo
Founded in 2007, the Japan Institute for National Fundamentals (国家基本問題研究所) 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 December 2020, its Director is Yoshiko Sakurai and Vice-Director is Tadae Takubo. Sakurai is a Co-Director of a group promoting a national movement for constitutional revision, Utsukushii Nippon no Kenpō o Tsukuru Kokumin no Kai (美しい日本の憲法をつくる国民の会), which working closely 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.