This essay looks at two war memorial museums that commemorate military dead in their respective nations: the War Memorial of Korea (hereafter WMK) in South Korea and the Yushukan, the Japanese war museum located in Yasukuni Shrine in Japan, both of which play crucial roles in enhancing conservative patriotic nationalisms in the two countries. Like other war memorial museums, the WMK commemorates the war dead who sacrificed their lives for the defense of the nation and imbues with patriotic spirit the younger generations who have no memory of war. Yet it also constructs an “ethnic” lineage of the nation, a sacrifice of forefathers for the children of the nation. It seeks to form a national subject based on the idea of Korean ethnic nation as originated from ancient times. The author shows how the museum constructs a tradition of military patriotism in terms of shared ancestry, ethnic purity, and familial belonging and how this process of making a “we” is closely related to the construction of “others,” namely North Korea, Vietnam, and Japan. For a comparison, it examines how the Yushukan seeks to revive imperial Japan's glorification of war based on the idea of the ethnic superiority of the Japanese. Comparing war museums in Japan and Korea, the author argues that despite their antagonistic discourses, they display similar strategies of representation: staging a ritual dedicated to the war dead as an embodiment of national identity. Although embedded in conflicting historical experiences of colonialism and postwar geopolitics, the two war museums demonstrate the growing obsession with the ethnic origin of the nation, which may develop into hostile attitudes towards resident ethnic minorities and foreigners in the increasingly globalizing contemporary social environment.