It was just hours before Japan's surprise attack on Pearl Harbor on Dec. 7, 1941. In Tokyo, Prime Minister Gen. Hideki Tojo was "perfectly relieved" and "tipsy," convinced Japan would win any conflict with the United States after having finished all the administrative procedures to wage war against American and British forces in Hawaii and Asia.

In a meeting with two influential bureaucrats — Internal Affairs Vice Minister Michio Yuzawa and Army Vice Minister Heitaro Kimura — at the Prime Minister's Office at 8:30 p.m. on Dec. 7, Tojo told them that Emperor Hirohito (posthumously known as Emperor Showa) was "not wavering" and showed no signs of "lingering regret" about the government's decision to end diplomatic talks with the U.S. and Britain to avoid war.

The revelations were uncovered in a five-page memo Yuzawa wrote that night that was discovered by Takeo Hatano, the owner of a secondhand bookstore in Tokyo. The memo's contents were first reported by the Yomiuri Shimbun on Monday. The Japan Times confirmed the text later in the day.