| 1984-90 | Yale University, Graduate School |
| Ph.D. (History), with Robert S. Lopez Memorial Prize, 1990 | |
| M.Phil. (History), 1987 | |
| M.A. (History), 1986 | |
| 1980-88 | University of Tokyo, Graduate School of Humanities |
| M.Litt. (Occidental History), 1982 | |
| 1976-80 | University of Tokyo, Faculty of Letters |
| B.A. (Occidental History), 1980 |
| 2023- | Professor Emeritus, University of Tokyo |
| 2004-2023 | Professor of Occidental History, University of Tokyo |
| (・Vice President, Mediterranean Academy of Japan, 2021-present) | |
| # Medal with Purple Ribbon, 2016 | |
| (・President, Historical Society of Japan, 2016-2020) | |
| (・President, Japan Society for Medieval European Studies, 2015-2019) | |
| ・Chair, Dept. of Occidental History, 2009-2012 | |
| (・Science Officer, Ministry of Education, 2008-2012) | |
| ・Chair, Division II (History), Faculty of Letters, 2008-2009 | |
| ・Director of Graduate Studies, Dept. of Occidental History, 2006-2009 | |
| 1993-2004 | Associate Professor, Institute of Cross-Cultural Studies, University of Tokyo |
| ・Chair, Dept. of Basic Theories, Institute of Cross-Cultural Studies, 1996-2004 | |
| # Collegium Mediterranistarum Award, 1994 | |
| # Premio Marco Polo, 1994 | |
| # Suntory Award, 1993 | |
| 1990-1993 | Associate Professor (Economic History), Hitotsubashi University, Tokyo |
| 1 | Robert S. Lopez Memorial Prize | Yale University, Graduate School | May 28, 1990 |
| 2 | Suntory Award (in History) | Suntory Foundation | December 6, 1993 |
| 3 | Collegium Mediterranistarum Award | Collegium Mediterranistarum | June 12, 1994 |
| 4 | Premio Marco Polo | Istituto Italiano di Cultura | October 14, 1994 |
| 5 | Medal with Purple Ribbon | Government of Japan | April 29, 2016 |
| 6 | Corresponding Fellow | Medieval Academy of America | January 3, 2024 |
| 1 | Japan Scholarship (for Undergraduate Students) | Nihon Ikueikai (The Japan Scholarship Foundation) | 1976-1980 |
| 2 | Japan Scholarship (for Graduate Students) | Nihon Ikueikai (The Japan Scholarship Foundation) | 1980-1985 |
| 3 | Harvard Yenching Institute Dectoral Scholarship for Junior Faculty | Harvard Yenching Institute, Harvard University | 1984-1988 |
| 4 | Toyota Foundation Research Fellowship | Toyota Foundation | 1988-1989 |
| 5 | Mitsubishi Foundation Research Fellowship | Mitsubishi Foundation | 1991-1992 |
| 6 | The Japan Foundation Fellowship | The Japan Foundation | 1995-1996 |
| 7 | The Murata Science Foundation Research Fellowship | The Murata Foundation | 1995-1996 |
| 8 | Department of Education Resident in Medieval Studies | The American Academy in Rome | 2002 |
| 9 | CMRS Distinguished Visiting Scholar | UCLA | 2009 |
| 10 | Willis F. Doney Member | Institute for Advanced Study (Princeton) | 2019 |
| Collegium Mediterranistarum (Mediterranean Academy of Japan) | Vice President | 2021-present | Executive Director | 2014-16 | Councilor | 1999-2017 |
| Historical Society of Japan | President | 2016-20 | Director | 1995-97 2003-05 2006-08 2009-11 |
| Auditor | 1994-95 1998-99 2020-present |
|
| Councilor | 1994-present | |
| Japan Society for Medieval European Studies | President | 2015-19 |
| Executive Director | 2010-13 | |
| Co-executive Director | 2008-10 | |
| Councilor | 2009-15 | |
| Preparatory Committee | 2007-09 | |
| Shigaku Kenkyukai | Councilor | 2004-present |
| Ministry of Education, Culture, Sports, Science and Technology | Science Officer of Humanities | 2008-12 |
| Science Council of Japan | Associate Member in Humanities | 2006-14 |
| The Japan Society for the Promotion of Science | Research Center for Science Systems Program Officer of Humanities |
2004-07 | The Japan Society for the Promotion of Science | The 21st Century COE (Centers of Excellence) Program Selection & Evaluation Committee of Humanities | 2002-03, 04-05, 07 |