evidence: This paper will focus on the Karafuto-jin – a community of former citizens of the Japanese colony of Karafuto (presently southern Sakhalin) – and their role in Japanese-Soviet/Russian relations. It will examine the Karafuto-jin’s identity formation as one of Japan’s "other" groups during the Karafuto era (1905-1945) and as a special group of returnees from Japan’s colonial empire (or Japan’s "burden citizens"), following their repatriation. In addition, the paper will discuss their resistance to the Soviet invasion and repatriation from Karafuto following Japan’s defeat in World-War II, as well as the impact of their political mobilization and activities on Japan’s policy towards the Soviet Union and later Russia. The paper will begin with a brief history of Karafuto, drawing on the early Japanese-Russian border settlements and the transformation of Karafuto’s administrative status during WWII. It will analyze the transformation of the Karafuto-jin’s sociopolitical status in the aftermath of the Karafuto’s cessation and handover to the USSR in 1945, exploring the nature of various problems associated with the return of the Karafuto-jin from the Soviet Sakhalin back to Japan and a lack of efficient government policy to help them repatriate, which prompted their political mobilization and the establishment of their official organization – the National League of Former Citizens of Karafuto ("Zenkoku Karafuto Renmei;" thereafter – the "Karafuto Renmei") – in 1949. [...] Keywords: Karafuto, Sakhalin, Kurile Islands, Japanese-Russian relations, Japanese-Soviet relations