| 2003 Aug | Established as a voluntary organization |
| 2003 Sept | Opened the website |
| 2004 Jan | Certified by Cabinet Office |
| 2007 Apr | Opened Yokohama branch office |
| 2008 May | Published 1st public relations magazine |
| 2010 Nov | Set up Environmental Solutions Dept. |
| 2011 May | Renewed the website |
| 2011 Nov | Authorized by National Tax Agency |
| 2012 Apr | Competent Authority transferred to Kanagawa pref. from Cabinet Office |
| 2012 May | Set up New Public Commons Support Section |
| 2012 Dec | Designated by Yokosuka City |
| 2016 July | Renewed the accreditation as an authorized NPO. |
| 2018 Jan | Renewed the designation of Yokosuka City Designated NPO |
| 2020 May | Integrated and reorganized the Departments (The Corporate Support Business Department and the Environmental Business Department were merged into the SMS Support Business department ,the Industry-Government-Academia Collaboration Support Department was integrated into the New Public Support Department, and the Public Affairs Department integrated into the Secretariat.) |
| 2021 Apr | Re-renewed the accreditation as an authorized NPO |
