Provides online a vast collection of documents relating to Ōhira Masayoshi (1910–1980), 68th and 69th prime minister of Japan (December 1978 to June 1980). These primary sources on postwar Japanese political history consist of diverse materials, ranging from handwritten diaries, notebooks and letters, to government agency (ministries of foreign affairs, international trade and industry, etc.) documents, manuscripts of speeches and responses to questions in the Diet, and election-related materials. Included also are records of interviews with important figures in politics and business conducted in the writing of Ōhira’s official biography.