or by retreating to mainland Japan. In the 9th month, a man who claimed to be an envoy of Sō Sadamori arrived in Korea. The conditions he presented seemed unsatisfactory to the Joseon. Taejong made similar demands of the envoy in the 10th month. According to the article on the 10th day of the first leap month of 1420 of Sejong Sillok, the same self-claimed envoy agreed to Korea's proposal to put Tsushima under the rule of Gyeongsang Province. On the 23rd of that month, the Korean court approved of this agreement. However, in later negotiations it was revealed that the envoy was not actually a representative of Sō Sadamori. In the 11th month of 1419, envoys of Ashikaga Yoshimochi visited Korea. In return, King Sejong sent Song Hui-gyeong to Japan. The diplomatic mission left the Joseon capital on the 15th day of the first leap month of 1420. The envoy continued on from Busan on the 15th day of the 2nd month. On the 21st, he met Soda Saemontaro on Tsushima as Sō Sadamori stayed with the Shōni clan in Hizen Province. He arrived in Kyoto in the 4th month. Having accomplished his mission, he left Kyoto in the 6th month, returning to Korea after completing negotiations with the Shōni and Sō clans in Kyūshū. He arrived in the capital in the 10th month, 1420. This trip corrected mutual misunderstandings between Japan and Korea. In Tsushima, Song received a protest from Soda Saemontaro over a Korean document that stated Tsushima's dependence on Korea. He warned of the Shōni clan's possible military action. Song realized that Sō Sadamori had not been involved in the previous negotiations, and also learned of the Sō clan's vassalage to the Shōni clan. These realizations overturned Korea's plans towards Tsushima. In Kyoto, Song clarified that the Joseon had no intention of invading Japan. On their way back, Korean envoys faced the Sō and Shōni's hard-line attitude toward the Joseon. In the 4th month of 1421, a letter under the name of Sō Sadamori demanded the return of Japanese captives and pointed out Korea's claim over Tsushima. It is noted that the Japanese envoy took advantage of the shogunate's authority, which can frequently be found in the Sō clan's later diplomatic talks with Korea. By the order of Taejong, Korea took a tough stance against the Sō clan. Although Soda's messengers visited Korea several times, they