This thesis addresses the issues of traumatic war memory concerning remembering and forgetting as presented construction of war memory in popular culture by closely examining the Japanese television anime series The Big O. The thesis proposes that the story told in The Big O can be seen as a vehicle for understanding why the Japanese wished to forget traumatic war memories related to the defeat of Japan in World War II. The Big O is a science fiction story that is set in a postwar defeated society. The protagonist of the story is Roger Smith, who searches for his lost memories. He is a social advocate for the people who want to recall their lost memories and acts as a negotiator in Paradigm City, a city that lost its own memories forty years ago. Drawing upon memory studies, the thesis explores various aspects of Japanese ambition and social concerns that emerged in Japan’s postwar society, including the national pride for the 1964 Tokyo Olympics, the rising economic success, and the revision of World War II’s history in school textbooks. The thesis examines dialogues by the characters in The Big O by paying attention to two major arguments surrounding memories: remembering and forgetting. By doing so, the thesis attempts to elucidate the ways in which war memories are at times remembered and often forgotten by those recovering from the wounds of war.