
| April 1981 - March 1983 | Research associate, Waseda University |
| April 1983 - March 1985 | Postdoctoral research fellow, Case Western Reserve University, U.S.A. |
| April 1985 - July 1988 | Research associate, Waseda University |
| August 1988 - Dec. 1997 | Associate Professor, Tokyo University of Agriculture & Technology |
| Jan. 1998- | Full Professor, Tokyo University of Agriculture & Technology |
| April 2007- March 2008 | Vice Dean, Institute of Symbiotic Science and Technology |
| April 2008- | Dean, Institute of Symbiotic Science and Technology |
| April 2008- | Director of University Library |