- Born: 1617
- Titles: Onaga peechin'
- Other Names: 牧 達村 (Maki Tasson / Mù Dácūn); 思徳 (Umituku)
- Japanese: 翁長 宗淳 (Onaga Sôjun)
Onaga peechin Sôjun, also known by the Chinese-style name Mù Dácūn, was a Ryukyuan scholar-official. He is known for his participation in a 1630 journey to Edo, during which he and several other teenage scholar-officials performed court music and dance at the Satsuma Edo mansion before Shimazu Iehisa, Tokugawa Hidetada, and Tokugawa Iemitsu.
The third head of the Maki/Mù house, he was born in 1617, and in his childhood was known by the name Umituku. Umituku was granted the aristocratic title of satunushi in 1621. In 1629 (at around the age of 12), he was selected to serve as gakudôji (young performer) alongside four or five other young scholar-aristocrats on a journey to Kagoshima and Edo. The embassy departed Naha on 1629/12/14, arriving in Kagoshima in the 2nd month of the following year. They then traveled to Edo, arriving at the Shimazu clan's mansion in the Shiba neighborhood in the 4th month. While in Edo, Retired Shogun Tokugawa Hidetada and active Shogun Tokugawa Iemitsu each paid visits to the mansion and enjoyed performances of Ryukyuan court music by Onaga and his compatriots. While passing through Kyoto on the way back to Kagoshima, the group performed music before Empress Meishô and the imperial court. They returned to Ryukyu in the 11th month, and performed music before the king and his court in the clothes they received in Edo.
- Uehara Kenzen 上原兼善, 「寛永期の琉球使節」, Nihon kinsei seikatsu ehiki: Ryûkyûjin gyôretsu to Edo hen 日本近世生活絵引：琉球人行列と江戸編、Research Center for Nonwritten Cultural Materials, Institute for the Study of Japanese Folk Culture, Kanagawa University 神奈川大学日本常民文化研究所非文字資料研究センター (2020), 167-168.