Kenpō Angya no Kai
Founded in 2004 by well-known intellectuals including Katsuto Uchihashi (economic critic) and Keiko Ochiai (writer), Kenpō Angya no Kai (憲法行脚の会) has been against constitutional revision.
Their website offers summaries of several anti-revision meetings, as well as statements from campaigners in this association. In the statements, the campaigners oppose constitutional revision. In 2014, they released a statement to criticize the security legislation to enable Japan to exercise the right to collective self-defense for ignoring pacifism determined in the constitution.
According to the website, this group has worked closely with the Social Democratic Party (社会民主党); a former SDP leader Takako Doi played a significant role in this group since it was founded. The anti-revision meetings sponsored by this group have featured guest speakers such as a SDP Diet member Mizuho, Fukushima, and a writer Makoto, Sataka.