(1) 1996. "Ryukyuan dispatches of Kan-sho in the early Ming Period: Focusing on the position of foreign students of Guozijian described on Nanyongzhi", Rekidai Hoan Kenkyu, 6/7(combined), pp.21-56 (in Japanese)
(2) 1999. "Ming dynasty's tributary relations with Ryukyu and its change - Particularly in the 14th and 15th Centuries -", The Journal of Oriental Researches, Vol.57, No.4, pp.1-35 (in Japanese)
(3) 2001. "The position of Ryukyu as a Tributary state and its change in the Ming Period", Haijiaoshi Yanjiu 2001-1, pp.76-97 (in Chinese)
(4) 2001. "The relation between Han'in Kango in the Ryukyu kingdom and Chaogong Kanhe in the Ming dynasty", The Collected Papers of 8th International Conference for Historical Study of Sino-Ryukyuan Relations, pp.337-358 (in Japanese)
(5) 2005. "The Ming Dynasty's "Tributary System" and Ryukyu: Focusing on Paying a Tribute as an Act" Workshop on Northeast Asia in Maritime Perspective: A Dialogue with Southeast Asia, The Asia Research Institute, National University of Singapore and The 21st Century COE Program <Interface Humanities>, Osaka University, pp.108-115 (in English)
(6) 2005. "Formation and expansion of Ryukyu as an emerging trade-center state: Focusing on a comparison with Hami and Mallaca", The Collected Papers of 9th International Conference for Historical Study of Sino-Ryukyuan Relations, pp.53-64 (in Chinese)
(7) 2006. "Notes for geographical works about Southeast Asia written in Chinese classics, focusing around the 18th century", History of Southeast Asia during invisible age: Deconstruction by reading textual source material (Research Report of JSPS Grant-in-Aid for Scientific Research (B), 2003-2005), pp.63-73 (in Japanese)
(8) 2008. "Trade Products of the Ryukyu Kingdom during its Old Period: Centered on Intercultural Relations", Relationship between Eurasia and Japan: Mutual Interaction and Representation (Research Report of Inter-Institutional and External Joint Research, National Institutes for the Humanities), pp.30-39 (in Japanese)
(9) 2008. "Expansion of tribute system and trade in Ryukyu Kingdom: Intraregional integration of 'Ryukyu arc' and trade system", KATO Yuzo, ONISHI Hideyuki and SASAKI Shiro(eds.)History of Social Interactions among the Inland Sea in East Asia ,Jimbun Shoin, pp.42-62 (in Japanese)
(10) 2008. "Ming China's international system and maritime world", MOMOKI Shiro(ed.)Research Guide for Maritime Asian History, Iwanami Shoten, pp.50-58 (in Japanese)
(11) 2008. "Several Aspects of Sea-Going Vessels of Ryukyu Kingdom in Old Ryukyu Period", Journal of East Asian Cultural Interaction Studies No.1, pp.221-248 (in Japanese)
(12) 2008. "Foreign Policy and Maritime Trade in the Early Ming Period: Focusing on the Ryukyu Kingdom", ACTA ASIATICA No.95, pp.35-55 (in English)
(1) September 2000 - August 2001: Visiting Scholar
Faculty of History, Fujian Teacher's University, Fuzhou, China
(2) 27th August 2001: Presentation on conference
"The position of Ryukyu as a Tributary state and its change in the Ming Period", The 9th International Conference of Ming History, Wuyishan, China (in Chinese)
(3) 7th November 2002: Presentation on conference
"Formation and expansion of Ryukyu as an emerging trade-center state: Focusing on a comparison with Hami and Mallaca", 9th International Conference for Historical Study of Sino-Ryukyuan Relations, Wuyishan, China (in Chinese)
(4) 19 July 2003: Presentation on workshop
"Foreign Policy and Maritime Trade in the Early Ming Period: Focusing on the Ryukyu Kingdom", Workshop on Southeast Asia in the 15th century and the Ming Factor, Asian Research Institute, the National University of Singapore, Singapore
(5) 8th December 2004: Presentation on conference
"The Ming Dynasty's "Tributary System" and Ryukyu: Focusing on Paying a Tribute as a Practice", The 18th International Association of Historians of Asia, Taipei
(1) 2nd December 1995: "Kansho of Ryukyu Kingdom in the early Ming period: Focusing on the position of foreign students of Guozijian in the Chinese tributary order", The 54th conference of Japan Society for Southeast Asian History, Naha (in Japanese)
(2) 12th January 2002: "The way of understanding a tribute: Compiling statistics for tributary cases based on Ming Shilu", Research forum "Asian History of interaction exploring material, human, and information", Tenri University, Tenri (in Japanese)
(3) 22nd November 2003 / 24th January 2004 / 14th Febrary 2004: Extension course "Ryukyuan people going across the sea", Tottori prefecture Library, Tottori (in Japanese)
(4) 10th August 2004: Lecture "Ryukyu Kingdom and East Asian international order", The 2nd nationwide workshop for teachers of history at the high school, COE program "Interface Humanities", Osaka University Graduate School of Letters, Toyonaka (in Japanese)
(1) The Society of Oriental Researches, Japan
4/1995-3/1996, 4/1997-3/2000: Member of editoral board
(2) The Society of Historical Research, Japan
(3) Japan Society for Southeast Asian Studies
1/2000-8/2000, 1/2002-12/2005: committee member from Kansai district
(4) The Asian Association of World Historians
(1) History around formation and development of Ryukyu Kingdom, especially before 17th century.
(2) International relationships between China and neighboring nations in the early modern era, focusing on tributary relationships and trade.
(3) Interaction of views of the world and geographical knowledge for foreign states between East Asia, in pre-modern era.