[1] He later returned his country[2] after being commissioned to shavetail of Imperial Korea.

[5] In 1905, he was joined to anti movement against of Japan–Korea Treaty of 1905 also he was identity of the soldiers.

[6] On 10 January 1906, he was one of the Attaché sent to Empire of Japan as a Cavalry Captain.

[7][8] While he was in Japan, Yun became a Cavalry major and received 4th Class of Order of the Sacred Treasure from Japanese Government.

[12] Empire of Japan considered Yun as a person needed caution.

[14] During the colonial period, Yun was required to cooperate with Japanese, which he refused.