Born:
 May 3, 1952, Chiba Prefecture
 
Education:
 1975 Sophia University, B.A.
 1977 Yale University, M.A. in Political Science
 1982 Yale University, Ph.D. in Political Science
 
Career:
 1981 Associate Professor, Faculty of Law, Sophia
    University
 1983 Visiting Fellow, Center for International Affairs,
    Harvard University
 1990 Professor, Faculty of Law, Sophia University
 2002 Ambassador Extraordinary and Plenipotentiary of Japan
    to the Conference on Disarmament, UN in Geneva
 2003 President, Conference on Disarmament, UN in Geneva
 2005 Member, House of Representatives
    Executive Member, Science Council of Japan
 2010 first elected to the Senate
 2013 Professor Emeritus, Sophia University
 2016 second elected to the Senate
 2022 third elected to the Senate
 
(Major posts in the Senate)
 2012 Chairperson, Special Committee on Okinawa and
    Northern Problems
 2022 Chairperson, Research Committee on Foreign Affairs
    and National Security
 2025 Chairperson, Committee on Environment
 
(Major post in the Government)
 2005 Minister of State for Gender Equality and Social
    Affairs
 
Note: The Sangiin, which had been known as the House of Councillors, is called the Senate in English as of August 2026.

(as of October 26,2026)