- Chinese/Japanese: 柴山 (Chái Shān / Sai Zan)
He traveled to Ryûkyû for the first time in 1425, dispatched by the Hongxi Emperor to perform the investiture of Shô Hashi, king of Chûzan, who was at that time still in the process of unifying Okinawa Island under his rule.
Chai later traveled to Ryûkyû three more times over the course of his lifetime, where he purchased many local materials from Ryûkyû, including unrefined lacquer sap and sword-polishing stones. He brought the investiture robes in 1427, and helped establish the temple Daianzen-ji in 1430. In 1428, King Shô Hashi erected an outer gate at his palace which he called the Chûzanmon, hanging on it a plaque bearing Chai's calligraphy.
In 1433, Chai Shan returned to Ryûkyû for the final time, with instructions from the Xuande Emperor to entrust Shô Hashi with overseeing the restoration of formal relations between the Ming and the Ashikaga shogunate of Japan.
Chai also planned journeys to Japan. He is said to have been severely reprimanded and punished by the Xuande Emperor following his return to China in 1434, though the reasons are unclear; some stories allege that he helped shelter a man named Hachirô who had killed a Japanese monk.