| 2009 - Present | Professor and Chairman, Department of Hematology, Juntendo University Faculty of Medicine, Japan |
| 2004 - 2009 | Professor and chairman, Dept. of Hematology/Oncology, Yamanashi University, Japan |
| 2000 - 2004 | Associate professor, Dept. of Hematology, Jichi Medical University, Japan |
| 1992 - 2000 | Assistant professor, Dept. of Hematology, Jichi Medical University, Japan |
| 1990 - 1991 | Research Fellow, New York Blood Center, USA |
| 1983 - 1992 | Clinical research fellow, Dept. of Hematology, Jichi Medical University, Japan |