Strained South Korea–Japan ties are frequently attributed to the use and abuse of history by national leaders. This article considers a more bottom-up explanation by examining how Korean civil society is taking three different pathways to exert influence on bilateral relations. First, non-governmental organizations are expanding domestic and international awareness of grievances regarding Japan's 1910–1945 colonization of the Korean Peninsula. Second, activists are pushing court cases in attempts to change legal interpretations and government policies. Third, certain civic groups demand maximalist positions on history and stigmatize cooperation with Tokyo. While influential over Korean public opinion, these efforts win few hearts and minds in Japan and complicate productive diplomacy. With particular attention to the 2015 Korea–Japan agreement for “comfort women” survivors and the 2018 South Korean Supreme Court decisions on wartime labor, this article unpacks the relationship between activist Korean civil society and historical reconciliation with Japan, offering implications for foreign policy and state-society relations.