- Born: 1930
- Japanese: 永積洋子 (Nagazumi Youko)
Nagazumi Yôko is a historian of 16th-17th century Japanese foreign relations. Specializing in particular on the history of Japanese relations with the Dutch East India Company, she was a prominent pioneer in critiquing the "closed country" (sakoku) view of Edo period Japan, and advocating a reexamination of how open and actively engaged Japan was in that period.
A graduate of the University of Tokyo, she taught there for many years and is today professor emeritus.
- "Ayutthaya and Japan: Embassies and Trade in the Seventeenth Century." in Kennon Breazeale (ed.). From Japan to Arabia: Ayutthaya's Maritime Relations with Asia. Bangkok: The Foundation for the Promotion of Social Sciences and Humanities Textbook Project, 1999.
- “From Company to Individual Company Servants: Dutch Trade in Eighteenth-Century Japan’.” On the Eighteenth Century as a Category Of Asian History. Aldershot: Ashgate, 147–172, 1998.
- “Japan’s Isolationist Policy as Seen through Dutch Source Materials.” Acta Asiatica : Bulletin of the Institute of Eastern Culture, no. 22 (1972).
- (with Shimada Ryūto), “Siamese Products in the Japanese Market during the Seventeenth and Eighteenth Centuries.” Large and Broad: The Dutch Impact on Early Modern Asia: Essays in Honor of Leonard Blussé 13 (2010): 147–65.
- “The Japanese Go-Shuinjo (Vermilion Seal) Maritime Trade in Taiwan.” Around and About Formosa: Essays in Honor of Professor Ts’ao Yung-Ho, Ed. Leonard Blussé, 27–41.
- Kinsei shoki no gaikô. 近世初期の外交. Tōkyō: Sôbunsha, 1990.
- Sakoku wo minaosu. 「鎖国」を見直す. Kokusai bunka kôryû suishin kyôkai, 1999.
- Shuinsen. 朱印船. Tokyo: Yoshikawa kôbunkan, 2001.
- Ronald Toby, Hayami Akira 速水融, et al, “Edo no kurashi ha kokusai kankei no naka ni” 「江戸の暮らしは国際関係の中に」, Kokusai kōryū 国際交流 59 (1992), 5.