| 1 | The Medieval Kingdom of Mystery --The Norman Kingdom of Sicily and Its Administrative Organization- | Annual Meeting of the Collegium Mediterranistarum (Mediterranean Academy) | Sophia University, Tokyo | 1990 June 3 |
| 2 | Baillis and Seneschals --The Administrative Structure of France during the Reign of Philip the Fair-- | Annual Meeting of the Historical Society of Japan | University of Tokyo, Tokyo | 1991 November 9 |
| 3 | History of Baillis and Seneschals --Historical Analysis of the Administrative Structure of France during the Reign of Philip the Fair-- | Annual Meeting of the Study Group of European History | Aoyama University, Tokyo | 1991 November 16 |
| 4 | Local Administrative System of France under Philip IV (1285-1314) -Baillis and Seneschals- | Annual Meeting of the Medieval Association of the Pacific | Seattle, USA | 1994 March 5 |
| 5 | Study of the Norman Kingdom of Sicily | Study Group of the History of Maritime | Chukinto Bunka Center, Tokyo | 1994 October 1 |
| 6 | L'organizzazione amministrativa nel Regno normanno | International Conference: Mezzogiorno - Federico II - Mezzogiorno: Convegno internazionale di studio in occasione dell' VIII centenario della nascita di Federico II | Potenza/ Avigliano/ Castel Lagopesole/ Melfi, Italy | 1994 October 18 |
| 7 | Study of the Norman Kingdom of Sicily | Institute of Asian and African Studies | Tokyo University of Foreign Languages, Tokyo | 1994 December 22 |
| 8 | Historiography of the History of Institutions of Norman Sicily. Some New Assumptions | Ecole des Hautes Etudes en Sciences Sociales | Paris, France | 1996 March 22 |
| 9 | Amiratus in the Norman Kingdom of Sicily --A Leading Office of Arabic Origin in the Royal Administration | Annual Meeting of the Medieval Association of the Pacific | Honolulu, USA | 1997 March 16 |
| 10 | Re-organization of Geo-political Units and States in Europe: The Middle Ages and Now | The University of Western Australia, | Nedlands, Australia | 1997 December 4 |
| 11 | Study about Medieval Sicily and Recognization of the Modern World | The Historical Society of the University of Hokkaido | Sapporo, Japan | 2001 September 21 |
| 12 | Arabic and Byzantine Elements in the Administration of Roger I(1071-1101) | Annual Meeting of the Historical Society of Japan | University of Tokyo, Tokyo | 2001 November 11 |
| 13 | La fondazione del sistema amministrativo normanno | International Conference: Congresso Internazionale di Studi: Ruggero I, Gran Conte di Sicilia, 1101-2001 | Troina, Italy | 2001 December 1 |
| 14 | Central Power and Multi-Cultural Elements at the Norman Court of Sicily | Universita di Palermo, | Palermo, Italy | 2002 March 20 |
| 15 | Roger I' s Conquest of Sicily and his Governing Policy | Universita di Palermo, | Palermo, Italy | 2002 March 22 |
| 16 | The Norman Court of Sicily: A Crossroads of Greek, Arabic and Latin Cultures | Department of Education Resident in Medieval Studies Lecture, American Academy in Rome | Rome, Italy | 2002 October 24 |
| 17 | The Norman Administration of Sicily and Southern Italy: Reconsideration of its Historiography and Perspective | Medieval Workshoptalks, American Academy in Rome | Rome, Italy | 2002 November 11 |
| 18 | The Meeting of Cultures in Sicily | Religious Minorities in the Norman World, Faculty of History, Cambridge University in conjunction with EU 'Culture 2000' Project on The Culture, Settlement and Migration of the Jews in medieval Europe | Cambridge, UK | 2002 November 28 |
| 19 | Kingdom and States in Medieval France | The Fourth Anglo-Japanese Conference of Historians 2003 | Kyoto 9-13 September 2003 | 2003 September 9 |
| 20 | Confrontation of Powers in the Norman Kingdom of Sicily: Kings, Nobles, Bureaucrats and Cities | Citta e vita cittadina nei Paesi dell'area mediterranea: secoli XI-XV | Adrano, Italy 18-22 novembre 2003 | 2003 November 18 |
| 21 | Power Structure of the Norman Kingdom of Sicily | 39th International Congress on Medieval Studies | Western Michigan University, Kalamazoo, Michigan, USA 6-9 May 2004 | 2004 May 8 |
| 22 | Confrontation of Powers in the Norman Kingdom of Sicily: Norman Kings, Arab and Greek Bureaucrats, and Feudal Lords | DESK-Symposium: Auf der Suche nach einem neuen Mittelalterbild - Genese "der anderen" in der europaeischen Kultur - | University of Tokyo, Tokyo | 2004 October 10 |
| 23 | Globalizing World and History | Keynote Lecture for the 75th Anniversary of the Historical Association of Hiroshima, Annual Meeting, Historical Association of Hiroshima | University of Hiroshima, Hiroshima | 2004 October 29 |
| 1 | Annual Meeting of the Collegium Mediterranistarum (Mediterranean Academy) | Chair of the Symposium:"Networks on the Sea" | Art College of Okinawa | 2001 July 1 |
| 2 | Seminar: Massimo Montanari, "Le transformazioni sociali ed economiche di epoca carolingia e l'ideologia dei tre ordines" | Chair, Organizer | University of Tokyo | 2001 October 11 |
| 3 | 99th Annual Meeting of the Historical Society of Japan | Chair of the Section for Medieval Europe | University of Tokyo | 2001 November 11 |
| 4 | Internatinal Symposium: Images and Reality: Japan, the World, East-West Exchange | Member of the executive committee, Chair and Commentator of the History Section | International Intercourse Building, International Academy, Tokyo | 2001 November 17 |
| 5 | International Conference: Congresso Internazionale di Studi: Ruggero I, Gran Conte di Sicilia, 1101-2001 | Chair | Troina (Enna), Italy 29 November - 2 December 2001 |
2001 December 1 |
| 6 | International Conference: Arte e Forma nella Sicilia Normanna | Chair | Bibliotheca Hertziana (Max-Planck-Institut fur Kunstgeschichte), The British School at Rome, Rome, Italy 6-7 December 2002 |
2002 December 6 |
| 7 | Seminar: Giles Constable, "Frontiers in the Middle Ages" | Chair, Organizer | University of Tokyo | 2003 October 30 |
| 8 | 101st Annual Meeting of the Historical Society of Japan | Chair of the Section for Medieval Europe | University of Tokyo | 2003 November 9 |