This chapter presents the history of labor management at Nippon Kokan (NKK) as a prototypical case in the postwar history of Japanese corporate management of the workforce. In the first postwar decade, big business launched a counterattack on the immediate postwar gains of labor unions; managers promoted massive technological innovation and introduced their version of American-style labor management. In 1953, the first stage of the iron and steel industry's postwar rationalization program was well underway. The first half of the 1950s was a period of transition in which the steel industry undertook its so-called first rationalization program. In the second rationalization program of 1955-1960, the steel industry introduced new technologies and more modern equipment to the entire production process, and steel makers began the full-scale Americanization of labor management as well. The chapter examines the substrata of change by looking into the way postwar unions thought about and acted in workplace society.