1973 April - 1977 March : University of Tokyo (Bachelor degree).
1977 April - 1979 March : University of Tokyo (Master degree).
1979 April - 1981 March : University of Tokyo (retired before taking Ph.D because of the employment as Lecturer at Chiba University).
1987 March : Ph.D at the University of Tokyo.
1981 April - 1987 March, Lecturer at Chiba University.
1987 April - 1989 May, Assistant Professor at Chiba University.
1989 June - 1996 June, Assistant Professor at Tokyo Institute of Technology.
1996 July - 2012 September, Professor at Tokyo Institute of Technology.
2012 October - 2018 March, Professor at University of Tokyo.
2018 April - present, Professor at Tsinghua University.
Emeritus Professor :
University of Tokyo
Tokyo Institute of Technology
1984, August - 1986, July : University of California at Berkeley, Research Associate supported by Japan Society for the Promotion of Science.
1991, October - 1992, September : Max-Planck Insitut f\"ur Mathematik, visiting member.
1994, August - 1995, May : Mathematical Sciences Research Institute at Berkeley, California supported by Japanese Ministry of Education.
2001, September - 2002, February : Institut des Hautes \'Etudes Scientifiques, visiting member.
2011, September - 2011, October : Tsinghua University, Mathematical Sciences Center, visiting member.
2016, January - 2016, March : Mathematical Sciences Research Institute at Berkeley, California (Simons Visiting Professor).
1990 Geometry Prize, Mathematical Society of Japan
2011 Autumn Prize, Mathematical Society of Japan