The article analyzes how the “comfort women” issue influences current relations between the Republic of Korea and Japan. In the early 20th century, Japan annexed Korea, and the memories of colonial-era humiliation are vivid in Korean collective consciousness. As a result, issues of the past often sour bilateral relations even today. Recently, Seoul has been actively pressing the issue of sexual slavery in Japanese military brothels, and differences over this seemingly irrelevant issue have impeded political and military cooperation. Articles on former sexual slaves (also called wianbu in Korean) have resurfaced time and again in Korean press throughout the 1940-80s, but the problem internationalized only in the 1990s, when a broad public discussion started. Although Japan maintains that the 1965 bilateral normalization resolved all issues of the past, Tokyo has several times offered official condolences and compensations to the victims, however Seoul found these steps or the tone thereof unsatisfactory. Most recently, in 2015, Abe Shinzō and Park Geunhye signed an agreement to close the wianbu issue, but the document irritated South Korean public and opposition, so Seoul abandoned it. President Moon Jaein, who came to power in 2017, continued this course and added pressure on related historical problems, such as Korean forced laborers in imperial Japan. As the crisis deepened, Tokyo introduced economic sanctions against South Korea (technically on unrelated grounds). Conflicts stemming from collective memory are a characteristic feature of North East Asian political culture. They are a popular tool in foreign and domestic policy of many countries. This, coupled with the irrational nature of nationalism and imperfection of regional security, makes issues of the past a very real threat to the present.