This article examines the influence of Baekje on document-based diplomacy (⽂書外交) in Wa (倭) during the late fifth century. In the latter half of the fifth century, when Yūryaku-tennō (雄略天皇, King Bu (武) of Wa) was on the throne in the Japanese archipelago, there was a large-scale movement of people from Baekje. The account in the Nihon Shoki concerning the arrival of skilled specialists (今來才伎) in Wa during the reign of Yūryaku-tennō reflects this historical reality.
Among these specialists were many artisans associated with handicraft production, but it is also likely that there were intellectuals proficient in the Chinese language and Classical Chinese. These Baekje-affiliated intellectuals made significant contributions not only to document-based administration (⽂書⾏政) in Wa but also to the conduct of document-based diplomacy between Wa and Chinese dynasties.
Earlier, Nishijima Sadao (西嶋定⽣) emphasized political relations between Chinese dynasties and surrounding polities—namely tributary relations—and the role of document-based diplomacy in maintaining them as a key factor in the formation of the Sinosphere. With regard to document-based diplomacy, he focused primarily on the bilateral relationship between Chinese dynasties and individual neighboring states. In contrast, this article examines document-based diplomacy by focusing on inter-polity relations in East Asia, as exemplified by the Baekje-Wa relationship, with particular attention to the cross-border movement of people. This analysis indicates that the formation of the Sinosphere, and the role of document-based diplomacy as its catalyst, should be understood not only through bilateral relations between Chinese dynasties and surrounding regions, but also through multilateral interactions within East Asia and the transregional mobility of people.