Along with investiture, tribute missions were another major component of diplomatic relationships between polities in East Asia. China received tribute missions, but so did other governments in the region.
Leaders were invited to send tribute missions on different schedules (e.g. once per year, once every three years, once every 11 years) depending on the closeness between the tribute-sending and tribute-receiving governments. Missions were expensive for the sending government but they also offered economic, political, and cultural benefits for participants. A single tribute mission could include hundreds of people: “scholar-officials, interpreters, physicians, alternates, messengers, and assistants”6 not to mention all the porters to carry the wide array of goods. For many decades of the Ming period, tribute missions were the primary way neighboring people could conduct legal trade with China. But as you can see from the meeting between Phung Khac Khoan and Yi Sugwang (described above), tribute missions were also chances for regional diplomacy and information-gathering.
6 Kang, David C. “Hierarchy and Legitimacy in International Systems: The Tribute System in Early Modern East Asia.” Security Studies, vol. 19, no. 4, 2010, pp. 591–622., https://doi.org/10.1080/09636412.2010.524079.