Eighty Sen’ was what the Tokyo Geishas who manicured the Admiral’s nails called him. The rate for a manicure was 100 sen, but Isoroku Yamamoto insisted on a discount since he had lost two fingers battling the Imperial Russian Navy. The naval commander who crafted the audacious raid that almost wiped out the United States Navy’s Pacific Fleet at Pearl Harbour often spent his evenings playing poker, and the Japanese board-game shogi, for high stakes. In addition to knowing the value of money, the Geishas learned, the old sailor had a shrewd grasp of strategy. “There is no chance of...