- 2013/04 - 現在 GS Council
- 2013/04 - 現在 Natural Sciences I, II, III, College of Liberal Arts, The University of Tokyo Lecturer
- 2007/09 - 現在 International Christian University Professor
- 2010/04 - 2016/03 Chair, Department of Mathematics and Computer Science, International Christian University
- 2007/04 - 2007/08 Graduate School of Pure and Applied Sciences, University of Tsukuba Associate Professor
- 2000/04 - 2007/03 Graduate School Of Pure and Applied Sciences, University of Tsukuba Associate Professor
- 2000/04 - 2007/03 Graduate School Of Pure and Applied Sciences, University of Tsukuba Associate Professor
- 2000/04 - 2002/03 Section of Mathematics, Graduate School of Science and Engineering, Sophia University Lecturer
- 2000/04 - 2002/03 Section of Mathematics, Graduate School of Science and Engineering, Sophia University Part-time Lecturer
- 1994/04 - 2000/03 Institute of Mathematics, University of Tsukuba Associate Professor
- 1997/03 - 1997/03 Département de Mathématique et Informatique, Université de Reims Professor
- 1997/03 - 1997/03 Département de Mathématique et Informatique, Université de Reims professeur de la classe exceptionnelle (professor of exceptional class)
- 1996/03 - 1996/08 Centre de Mathematiques, Ecole Polytechnique Researher Postdoc
- 1996/03 - 1996/08 Centre de Mathematiques, Ecole Polytechnique chercheur (researcher)
- 1992/04 - 1994/04 Graduate School of Mathematical Sciences, The University of Tokyo Research Assistant
- 1991/10 - 1992/03 Section of Basic Mathematics, Department of Basic Sciences I, CLA, The University of Tokyo Research Assistant
- 1988/09 - 1991/09 Centre de Mathematiques, Ecole Polytechnique Researher Postdoc
- 1988/09 - 1991/09 Centre de Mathematiques, Ecole Polytechnique chercheur (researcher)