Others

Nihon Seinen Kaigisho | Junior Chamber International Japan

日本青年会議所

Junior Chamber International Japan has promoted constitutional revision. They published a draft for constitutional revision in 2005 and started holding town meetings all over Japan in 2008. Here is the web page for their conference for constitutional discussion. In July 2017, this conference held a debate regarding constitutional revision. The main debate theme was regarding “if the constitution should specify free education”.
 

Tōkei Sūri Kenkyūjo | Institute of Statistical Mathematics

統計数理研究所

「国民性の研究」>「#8政治的態度」>「#8.11憲法改正に賛成か」(Japanese Live Site) | ["Research on National Character" > "#8 Political Attitude" > "#8.11 Constitutional Revision"]
This institute was founded in 1944 as an organization for statistical studies under the direct control of the Ministry of Education. They started a project entitled “国民性の研究 [Research on National Character]” in 1953. They have held a survey once every five years since then and released the survey results and reports on this web page. They included a question about constitutional revision in the 1993 survey. The question asked if the voters are in favor of or opposed to constitutional revision.