This chapter focuses on the persistence of colonial elements in national sovereignty through the case of the internment camps for “illegal” Korean immigrants in Sasebo, Japan. The islands in the strait area between Japan and the Korean Peninsula, under the U.S. occupation, served as a stage where many irregular migrants crossed from Korea to Japan. Through their suppression, the national borders were re-demarcated. Historical documents show that the practices in the “spaces of exception” in Sasebo materialized the dialectic of exclusion and inclusion, in which the arbitrary “illegitimacy” was constructed, and all the former colonial people were subjected to authorities’ extralegal demands. Sasebo, as the hinterland of the islands in this strait, also exemplified the fragmented nature of the marginality and centrality of these islands.