Having taken a quarter-century to compile, the project relied on some 40 new sources, most notably the diary and notes of Saburo Hyakutake, an admiral who served as Court Chamberlain from 1936 to 1944. But, while acknowledging the enormous scale of the undertaking, specialists seem to agree that the new account offers no earth-shattering findings or innovative interpretations concerning Hirohito’s many and changing roles in the most tumultuous period of Japan’s modern history.