The purpose of this dissertation is to identify the underlying conditions that account for the shift of Japanese public perception in the early 1990s in terms of past war memories, shedding light on the social memory studies of former aggressor nations. In this dissertation, I shall show how the perception of past wrongs and the sense of guilt regarding them are conditioned by the perception of external others and their relative significance. More concretely, I will posit the perception of external others (China and South Korea) as a cultural context. This is contextual relevance that matters when individuals retrieve, accept, or reject certain national memories of past wrongs and certain interpretations of historical events, which quite often accompany certain expressions and feelings toward the past and its victims through specific gestures (such as apology). Through this effort, the study will also reveal the underlying structure of Japan's public perceptions about Japan (self-image), Asia (especially China and South Korea) and the U.S. (others), and Japan's international relations throughout the post-War years. My unit of analysis is a time period, and empirical attention will be paid to how people (i.e., the public) think. This is a plausibility probe case study in post-War Japan, and the extensive coverage of the major opinion surveys in the post-War years (1945-1995) will be the major source of data.