The purpose of this study is to clarify how Shimane Prefecture gained approval to pass the “Takeshima Day”
ordinance after having formed sister government ties and making an extensive effort to develop friendly relations with North Gyeongsang Province. Shimane Prefecture had a sense of crisis when the South Korean Government claimed effective control of Takeshima Island, and demanded that the Japanese Government would tackle the Takeshima issue as a national movement. Shimane Prefecture urged the Japanese Government to establish “Takeshima Day” as well as “Northern Territories Day,” and did not have an intention to do so, initially. As a result, Shimane Prefecture enacted the ordinance in 2005. However, it was not endorsed by the Japanese Government. Then Japan- South Korea relations deteriorated, and eventually local interaction with North Gyeongsang Province was suspended due to the establishment of the ordinance. Shimane Prefecture and North Gyeongsang Province shared a recognition that the territorial dispute should
be solved diplomatically by the two nations. Therefore, Shimane Prefecture thought the territorial dispute and local interaction were different matters. However, North Gyeongsang Province considered that Shimane Prefecture had become involved in the territorial dispute.