Over 78 years have passed since WWⅡ and it is imperative that we pass down the harsh experience of the war and afterwar to future generations. Moreover, the reality of the “postwar” society needs to be reexamined given the raging wars under the Cold War occurred in East Asia, such as the Korean War and Vietnam War. Considering the aforementioned issues, “postwar” photographers have produced valuable works for future generations, capturing people who have experienced a variety of social changes. However, many issues remain regarding how to use photographs, especially in modern Japanese history, although historians place a high value on its potential for describing the postwar history in a different way. By contrast, a review of previous research indicates that images evoked by photographs have generally been discussed by focusing almost solely on respective works. In other words, little was known about how photographers faced and understood the reality of postwar Japan. For example, Shōmei Tōmatsu was one of the most influential Japanese photographers of the postwar era. His shock and reflection at not knowing the reality of Nagasaki after the atomic bombing in the early 1960s led him to spend several decades following and filming survivors. Thus, the authors devised and applied “photography in practice (shashin-jissen).” This is an original methodology for systematically redefining the expression of photographers’ intentions, which are constantly deepened beyond the immediate reality through photographing. The authors adopted “photography in practice” and focused on Tōmatsu’s postwar works to clarify the reality of the postwar society that he once continued to express. This was achieved by reconstructing various media of expression along the trajectory of his photographic activities, such as photo collections, magazines, and newspaper articles, while considering the social conditions of the time. On the other hand, “photography in practice” was inspired by folklorist Kunio Yanagida’s theory of feelings. Additionally, it shares common ground with life-history research. Hence, to systematize this methodology more precisely, it is necessary to reinforce the theoretical backgrounds. Therefore, this study reconsiders the methodological potential of “photography in practice” by reviewing the relationships among theories that off er important suggestions. In conclusion, “photography in practice” closely focuses on facts captured through the photographer’s mind, which deepens through the act of photography as “feelings” according to Yanagida’s theory of feelings. Notably, it is characterized by the inability to separate objects into facts and feelings because they are “facts observed through feelings” of the perceiving subject. In addition, our methodology examines the relationship between social change and the individual based on objective facts, which has the analytical perspective in common with life-history research. Further, we hope to pass down “postwar history” from the perspective of photographers on future generations by our own photographic activities in the field.