April 1989 - December 1991
Dept. of Mathematics, Aichi Univ. of Education Assistant professor
January 1992 - March 2007
Dept. of Mathematics Education, Aichi Univ. of Education Associate professor
April 2012 - March 2020
Faculty of Education, Soka University Dean
April 2007
Faculty of Education, Soka University Professor
April 2009
Seki Kowa Research Institute of Mathematics, Yokkaichi University Visiting fellow
April 2020
Soka University Vice President