Research Assistant, Faculty of Law, The University of Tokyo, 1971. Associate Professor, Faculty of Law, The University of Tokyo, 1974. Professor: Faculty of Law, The University of Tokyo, 1985; The University of Tokyo Graduate Schools for Law and Politics, 1991-2009; Chuo University Law School, 2009—. Dean of Faculty of Law, Dean of The University of Tokyo Graduate Schools for Law and Politics, 2004-2007. Managing Director, Executive Vice President, The University of Tokyo, 2007-2009. Professor Emeritus, The University of Tokyo, 2009.