In 1928, he had become involved in several rural social movements, which were known as "farmers' enlightenment and reading societies". Yun wrote a textbook called "Farmers Readers". It was used at evening classes to teach literacy to poor young adults who could not attend school in rural areas. He also founded a group called "Re-invigoration" to promote the revival of farming villages. After successfully organizing a well-attended rural cultural festival in which he performed a sketch entitled ""The Rabbit and the Fox"", he came to the to attention of the "Tokubetsu Kōtō Keisatsu", the Japanese Secret police in Korea tasked with investigating people and political groups that might threaten the Empire of Japan.