Over the course of Japan's Edo period, the Ryà «kyà « Kingdom sent eighteen , the capital of Tokugawa Japan. The unique pattern of these diplomatic exchanges evolved from models established by the Chinese, but without denoting any predetermined relationship to China or to the Chinese world order. The Kingdom became a vassal to the Japanese feudal domain (han) of Satsuma following Satsuma's 1609 invasion of Ryà «kyà «, and as such were expected to pay tribute to the shogunate; the missions also served as a great source of prestige for Satsuma, the only han to claim any foreign polity, let alone a kingdom, as its vassal.
Royal princes or top-ranking officials in the royal government served as chief envoys, and were accompanied by merchants, craftsmen, scholars, and other government officials as they journeyed first by sea to the Ryà «kyà «-kan (çÂÂçÂÂ館) in Kagoshima, an institution which served a role similar to a consulate for the Ryà «kyà « Kingdom, and then on by land to Edo. Missions traveled as a part of Satsuma's regular missions to Edo under the sankin kà Âtai system, the Ryà «kyà «an envoys and their entourage considerably outnumbered by the Japanese envoys and entourage from Satsuma, and were housed in the Shimazu clan residences during their time in Edo. Even so, they were still regarded as diplomatic missions from a foreign country. This was reflected in the envoys' reception in Edo, in the associated rituals and meetings. Ryà «kyà « was, however, regarded as being quite low in the hierarchy of foreign countries in the shogunate's world view. While the Ryà «kyà «an embassies paralleled in many ways those sent by Joseon Dynasty Korea in the same period, various aspects of the Ryà «kyà «an envoys' reception reflected their lower status in the shogunate's view. Since envoys from both Korea and Ryà «kyà « were not equals with the shà Âgun, intermediaries represented the shogunate in meetings with the envoys; while Korean envoys met with members of various high-ranking families (the kà Âke), envoys from Ryà «kyà « were met by a lower-ranking master of ceremonies, the sà Âshaban.
The nature and composition of these Ryà «kyà «an missions to Edo evolved over the course of time. The earliest Ryà «kyà «an mission was received in Kyoto in 1451 (Hà Âtoku 3, 7th month ) Mention of this diplomatic event is among the first of its type to be published in the West in an 1832 French version of by Hayashi Shihei. The essential character of these diplomatic expeditions mirrored the Ryà «kyà «an embassies to the Qing court in Beijing. The best extant description of these embassies is found in Tsà «kà  ichiran, compiled by Hayashi Akira in 1853. Japanese modifications to the well-established concepts and patterns of foreign relations of Imperial China developed as conditions changed.
Every mission was conducted either to congratulate a new shà Âgun on his succession or in connection with the accession of a new king of Ryà «kyà «. In the latter case, approval and formal recognition of the new king would be formally requested of both the Shimazu clan lords of Satsuma and of the shogunate, but the request was essentially simply a matter of ritual, and none were ever denied.
Extensive efforts were made to stress the foreignness of the costume, language, customs and art of the Ryà «kyà « Kingdom, emphasizing the glory and power of the Shimazu clan of the Satsuma Domain, the only daimyà Âs (feudal lords) in Japan to enjoy the fealty of a foreign kingdom. The missions served a similar function for the shogunate at times, helping to create the image that the shà Âguns power and influence extended overseas. The third Tokugawa shà Âgun, Tokugawa Iemitsu, called for an embassy to be sent from Ryà «kyà « in 1634, as his predecessor Tokugawa Hidetada had done with a Korean embassy in 1617, to provide a show for the Imperial court and daimyà Âs of the shà Âguns power.
Numerous woodblock prints and paintings of the exotic and brightly colored costumes and banners of the Ryà «kyà « delegation were produced, and bought and sold by commoners and samurai alike.
The Kingdom of Ryà «kyà « was invaded by forces from the Satsuma Domain in the 12th year of Keichà  (1609). King Shà  Nei and a number of royal advisors and government officials were taken back to Kagoshima and then to Sunpu, where they met with retired shà Âgun Tokugawa Ieyasu. The delegation continued north to Edo for a formal audience in the shogunal court of Tokugawa Hidetada. Upon returning to Kagoshima, the king and officials were required to sign oaths of loyalty to Satsuma. Secondary sources, i.e. history books, often count this as the first tribute mission.
No formal tribute/diplomatic mission was sent in this year, but three high-ranking officials from the Ryà «kyà « government journeyed to Edo to perform before shà Âgun Tokugawa Iemitsu.
The 1649 mission was headed by Prince Gushikawa Chà Âei.ãÂÂChà Âei was the seventh son of Shà  Kyà «, son of King Shà  Gen (r. 1556âÂÂ72).
Prince Nago led a mission in 1682 to congratulate shà Âgun Tokugawa Tsunayoshi on his succession. He alone of the members of the mission was granted an audience with the shà Âgun; by contrast, the Korean representatives received several months later included three ambassadors and seven or so aides and pages. This is but one of many differences seen in the reception of Korean and Ryà «kyà «an embassies, reflections of the different levels of status the two countries held in the Japanese view.
The reception for Prince Nago was attended by all daimyà Âs below the fourth court rank; a great number of samurai lords, but of relatively low rank. In presenting formal greetings on behalf of King Shà  Tei, he bowed nine times "on the fourth mat below the Lower State <nowiki>[and]</nowiki> withdrew" and then presented obeisances on his own behalf from the veranda. This, too, reflects a lower status than the Korean ambassadors, who made only four and a half bows from the second mat below the Middle Stage. Historian Ronald Toby, by way of contrasting the treatment of the two embassies, also adds that the Ryà «kyà «ans were offered no grand banquet as the Koreans did, nor were they bade farewell by the rà Âjà « (Council of Elders; chief shogunal advisors) when they left Edo for home, as the Korean envoys did.
Mission to Edo included 168 from Ryà «kyà «, far exceeding the size of any previous mission. This is a reflection in large part of the relative prosperity of the kingdom under the guidance of royal advisor Sai On.
The largest mission in the history of the practice journeys to Edo, led by Princes Yonagusuku and Kin. Tei Junsoku, Confucian scholar and influential educational reformer, accompanied the mission as the Chief of Correspondence. Tei met with Japanese Confucian scholars Arai Hakuseki, Ogyà « Sorai, and Dazai Shundai. Hakuseki would later write a history of the Ryà «kyà « Islands, entitled , based on discussions with Tei Junsoku and others during this envoy mission; Shundai likewise included passages about the Ryà «kyà «s in his .
Discussions between the Ryà «kyà «an emissaries and their Japanese counterparts concerned in part problems faced by the Ryà «kyà « Kingdom. Economic policies put into place in the ensuing years were patterned after recent Japanese policies under shà Âgun Tokugawa Tsunayoshi. The influence of this 1714 mission was particularly strong in drawing the attention of the shogunate to the affairs of the Ryà «kyà « Kingdom.
An embassy from the Ryà «kyà « Islands arrived in Japan in the 1st year of Kan'en (1648), and another embassy arrived in the 2nd year of Hà Âreki (1752).
The king of the Ryà «kyà « Islands sent an ambassador to the court of Empress Go-Sakuramachi in the 1st year of Meiwa (1764); and presentations of Ryukyuan music were among the offerings presented by the Ryukyuan ambassador.