This article seeks to provide an overview of the history of Hiroshima’s reconstruction mainly from the political perspective. Its aim is to describe the history of Hiroshima as a process of peacebuilding. The history of Hiroshima which this essay describes is as follows; Hiroshima took one type of peacebuilding policies at the local city level during the early modern “Meiji” period in which Japan sought to overcome the structure of internal armed conflicts. The attempt was not successful at the beginning. However, some accidental factors led Hiroshima to develop as the “military city.” The dropping of the atomic-bomb did not only bring about physical destruction; it also created a need for Hiroshima to reflect upon past peacebuilding policies and search for new peacebuilding policies. The history of Hiroshima after the Second World War is an example of modified peacebuilding polices at the local city level.