For nearly 18 months, Admiral Isoroku Yamamoto the commander of the Japanese Combined Fleet fought the Japanese Army and the Imperial Naval General Staff on the need to strike Pearl Harbor at the outset of war with America. The General staff wanted the fleet carriers for operations in the south, but Yamamoto knew everything depended on the Pacific Fleet being neutralized. At one point the Pearl Harbor operation was only approved when Yamamoto, his staff, and all of his senior commanders threatened to resign. The entire time was spent planning, politicking, and solving the numerous technical problems involved in striking the American Pacific Fleet in the shallow waters of Pearl Harbor in far off Hawaii. But on 26 November 1941, the hard work passed into the hands of the operation’s commander, Japan’s premier carrier admiral Vice Admiral Chiuchi Nagumo, when the Kido Butai secretly departed Hittokapu Bay in the Kurile Islands for the long journey east.
The Kido Butai, the “mobile strike force” of the Imperial Japanese Navy, was the most powerful naval fleet ever seen in history up to that point. It consisted of three of the five Japanese carrier divisions, and all of Japan’s big fleet carriers. These carriers: the Kaga, Akagi, Soryu, Hiryu, Shokaku, and Zuikaku, could together put the 414 modern fighters, dive bombers, and torpedo/level bombers of the 1st Air Fleet into a devastating first strike. Additionally every plane was superior to anything comparable flown by the Americans. This massive strike force was further escorted by two battleships, three cruisers, nine destroyers, eight tankers, and 23 submarines. Finally, the Kido Butai carried four midget submarines for penetrating the tight defense of the harbor entrance.
The trip would take ten days. They were scheduled to arrive at the launch point just north of the Hawaiian Islands on the morning of 7 December, 1941.