Following the postwar reconstruction period, Japan enjoyed rapid economic growth from the mid-1950s to the mid-1970s. During those years, Japanese companies, mainly manufacturers, established the Japanese-style production system. However, the coal industry was left behind by the economic growth. One reason for this was the “energy revolution” that occurred in the mid-1950s, namely the replacement of coal with oil as the main energy source. This shift turned coalmining into a declining industry. Coal companies were forced into corporate restructuring, triggering an era of rationalization. Facing this situation, Taiheiyo Coalmine Co. Ltd. took the modernization of its management system further than other mines. As a result, it took up a shift to the Japanese-style production system. This transformation was developed by the joint efforts of labor and management and the company survived through to the twentieth century and still continues to operate today run by the successor to Taiheiyo Coalmine. This paper sets out to elucidate the transformation of the work environment and the change in workers’ attitudes in the 1960s and 1970s.