Sanshikan
The Sanshikan (三司官), or Council of Three, was a government body of the Ryūkyū Kingdom, which originally developed out of a council of regents.
It emerged in 1556, when the young Shō Gen, who was mute, ascended to the throne of Ryūkyū. The council of regents that formed in order to handle this challenge and manage the country on the king's behalf soon grew into an established and powerful government organ. Shō Gen died in 1571, but the Council remained, acting alongside the successive kings in managing the affairs of government. In fact, the Articles Subscribed to by the King's Councillors, which bound the royal government in loyalty and servitude to the Japanese daimyo of Satsuma, explicitly prohibit the king from "entrust[ing] the conduct of public affairs in the islands to any persons other than San-shi-kuan"
Over time, the Sanshikan eclipsed the power and prestige of the sessei, a post which is often translated as "prime minister," and which served as chief royal advisor. Candidates to join the Council of Three had to live in Shuri, the capital, and had to pass tests of both merit and birth; they had to be of proper aristocratic heritage, and to pass tests of knowledge of literature, ethics, and other classical Chinese subjects. These exams were very much akin to those taken by scholar-bureaucrats in China, but were less strict.