This study explores the entire process of black-market tobacco from the production of raw materials to the distribution of products in Japan to examine the mechanism leading the black market to serve two functions: ensuring the security of lives and providing an essential outlet for entrepreneurial creativity. As the defeated countries of the Second World War were severely ravaged by famine, they deepened their reliance on the black market until the end of the 1940s. Japan also faced the same major challenges to its survival as Germany and Italy. By analyzing the authority’s handwritten inspection reports, this study reveals the black market’s growth mechanism. The black market had a division of labor structure, and the specialization promoted the market growth by reducing technical and financial barriers to newcomers and securing the participants’ profit. Although the authorities strictly cracked down on illegal actions, their measures ironically helped the black marketeers’ business to become more lucrative.