He also serves as a Representative to the Arigatou Foundation, which was established by Myochikai.

The foundation is dedicated to spreading the charity and mercy of their leader, the late Mitsu Miyamoto, throughout the world and to praying for the safe and sound development of children—for those suffering and for the souls of those who have died. Rev. Miyamoto serves on the boards of several not-for-profit organizations.

Rev. Miyamoto is the Auditor of the Japanese Association of Religious Organizations (Nishuren), the Auditor of the Japan Centre for Conflict Prevention, the Councilor of the Niwano Peace Foundation, the

Director of the Federation of New Religious Organizations of Japan (Shinshuren) and a Council Member of the WCRP Japan Committee.