1955
LLB at the University of Tokyo, Faculty of Law

1957
LL.M at Masters Course, Tokyo University Post Graduate Sociology, Entered the Legal Training and Research Institute (11th graduating class)

1959-1972
Senior Lecturer, Associate Professor of Rikkyo University, Law Faculty, Associate Professor of Hitotsubashi University

1963
LL.D at Tokyo University, Doctors Course, Post Graduate Sociology

1965-1967
Study in the former West Germany as a research scholar of the Alexander von Humboldt Foundation

1972-1996
Professor of Hitotsubashi University

1996
Emeritus professor of Hitotsubashi University Professor of Surugadai University, Law Faculty

1997
Admitted to the bar (Daiichi Tokyo Bar Association) Special Counsel of Abe, Ikubo & Katayama

1999
President of Surugadai University

2007
Chancellor of Surugadai University