- 2022/04 - 現在 Kyushu Lutheran College Academic Adviser
- 2020/04 - 現在 Keio University Emeritus
- 2020/04 - 2023/03 慶應義塾大学法学部講師 法学部 講師
- 2020/04 - 2023/03 Fukui Prefectural University Administrative Adviser
- 2019/04 - 2020/03 Director, Center of Data Archive for Social Sciences
- 2013/04 - 2020/03 Professor of Political Science at Keio University
- 1992/04 - 2020/03 Professor of Graduate School of Law and Political Science at Keio University
- 2017/05 - 2019/03 Director, Center of Data Archive for Social Sciences (SU)
- 2000/04 - 2019/03 Visiting Professor at Seigakuin University
- 2017/04 - 2018/03 Senior Research Fellow of Global Research Institute (KGRI)
- 2016/04 - 2017/03 Senior Research Fellow of Global Security Institute
- 2013/04 - 2014/03 Lecturer at Yokohama National University
- 2012/04 - 2013/03 Professor of Institute of Urban Innovation at Yokohama National University
- 2012/04 - 2013/03 Visiting Professor of Political Science at Keio University
- 2003/10 - 2012/03 Director, Center of Civil Society at Keio University
- 1991/04 - 2012/03 Professor of Political Science at Keio University
- 2006/04 - 2011/09 Visituing Professor at the Open University of Japan
- 1997/10 - 1997/12 Keio Fellow of Downing College Cambridge, U.K.
- 1995/04 - 1996/12 member, Ph.D. thesis committee,University of Chhhicago, Chicago, U.S.A.
- 1994/08 - 1996/12 Visiting Scholar,Center for Janpanese Studies,University of California, Berkeley, U.S.A.
- 1986/04 - 1991/03 Associate Professor of Political Science at Keio University
- 1985/08 - 1986/07 Visiting Reserch Fellow,Center of International Studies,Princeton University, U.S.A.
- 1982/04 - 1986/03 Assistant Professor of Political Science at Keio University
- 1984/08 - 1985/07 Visiting Assistant Professor,Department of Political Science,University of Michigan, U.S.A. Visiting Reserch Fellow,Center for Political Studies,Institute for Social Reserch,University of Michigan, U.S.A.