As the Japanese often used the excuse of protecting Korean emigrants to enlarge their sphere of influence in Northeast China, the views of Chinese government and people towards Korean emigrants changed after the mid of 1920, especially after the exposure of Tanaka Memorial and the Wanpaoshan Incident. Korean emigrants used to be considered as independent activists in China, but now they were generally considered as the vanguard of Japanese invasion. Relationship between local Chinese and Korean emigrants became tense. After the Chinese government signed the treaty with the Japanese government on 11 June 1925 to assist the Japanese get rid of Korean independent activists in Northeast China, the Fengtian clique began to use this treaty to expel and persecute Korean emigrants and began to take back the farm lands cultivated by non-naturalized Korean emigrants or put on more restrictions. Naturalized Korean emigrants, however, continue to have the rights to own farm lands. Under these circumstances, Korean emigrants in Northeast China began to have the consensus of becoming naturalized and actively seeking local autonomy. Many anti-Japanese Korean organizations took measures to protect Korean emigrants and negotiated local Chinese governments into making concessions or acquiescence. In 1928, Zhang Xueliang replaced the Beiyang government flag in Northeast China with Republic of China’s flag, after the Huanggutun incident. Many Korean independent organizations seized this good opportunity to encourage Korean emigrants in Northeast China to apply for Chinese citizenship. On 10 September 1928, Korean emigrants in Northeast China established the Korean autonomy organization ‘Korean Fellow Association’ (韓橋同鄕會). In April, the leader of Korean Fellow Association Cui Dongwu went to Nanjing and hold negotiations with the central Chinese government on various issues about Korean emigrants’ naturalization and autonomy. These negotiations helped to facilitate the naturalization process for Korean emigrants, but did not make success in asking for Korean autonomy. In 1931, Japan staged the Mukden Incident and invaded Northeast China by force, then established a puppet state called Manchukuo. On 14 September 1936, the Japanese set up a special organization (滿鮮拓殖會社) and began to migrate Korean farmers to Northeast China in a planned systemic way. In 1945, when Japan surrendered at the end of World War II, there were more than 2.16 million Korean emigrants living in Northeast China. Among them, about 700,000 returned to Korea after the end of World War II.