Internal documents of the National Railway Workers Union (NRU) formed in February 1946, donated by the NRU to the Faculty of Economics at the University of Tokyo in 1997 when the union hall—formerly in front of Tokyo Station—moved to another location. Predominantly concerning wages, the material covers postwar reforms to the pay system, staff quotas and human resource management; internal discussions at department head level and debates at worker gatherings by job function on labor allowances and wages; surveys on the lifestyles and views of national railway workers; and the fierce labor-management clashes of the Marusei era. Covering 40 years from the end of the war to the splitting and privatization of Japanese National Railways, as a primary source on labor in Japan this is one of the most extensive, and best. As a rare resource offering an inside look at the workings of the NRU, a leading player during the peak years of the labor movement, when it was said “Once the army, now the General Council (of Trade Unions)”, with a consistently high profile in postwar Japan as the nation progressed from economic recovery to high growth to economic giant, this is highly recommended to researchers across all associated disciplines.