Question: Operation Vengeance was designed to kill the leader of which Japanese military body?

full_context: Document 1: Japanese Instrument of Surrender: The Japanese Instrument of Surrender was the written agreement that formalized the surrender of the Empire of Japan, marking the end of World War II. It was signed by representatives from the Empire of Japan, the United States of America, the Republic of China, the United Kingdom of Great Britain and Northern Ireland, the Union of Soviet Socialist Republics, the Commonwealth of Australia, the Dominion of Canada, the Provisional Government of the French Republic, the Kingdom of the Netherlands, and the Dominion of New Zealand. The signing took place on the deck of USS "Missouri" in Tokyo Bay on September 2, 1945.
Document 2: Japanese naval codes: The vulnerability of Japanese naval codes and ciphers was crucial to the conduct of World War II, and had an important influence on foreign relations between Japan and the west in the years leading up to the war as well. Every Japanese code was eventually broken, and the intelligence gathered made possible such operations as the victorious American ambush of the Japanese Navy at Midway (JN-25b) and the shooting down of Isoroku Yamamoto in Operation Vengeance.
Document 3: Battle of Savo Island: The Battle of Savo Island, also known as the First Battle of Savo Island and, in Japanese sources, as the First Battle of the Solomon Sea (第一次ソロモン海戦 , Dai-ichi-ji Soromon Kaisen ) , and colloquially among Allied Guadalcanal veterans as The Battle of the Five Sitting Ducks, was a naval battle of the Pacific Campaign of World War II between the Imperial Japanese Navy and Allied naval forces. The battle took place on August 8–9, 1942 and was the first major naval engagement of the Guadalcanal campaign, and the first of several naval battles in the straits later named Ironbottom Sound, near the island of Guadalcanal.
Document 4: Guadalcanal Campaign: The Guadalcanal Campaign, also known as the Battle of Guadalcanal and codenamed Operation Watchtower was a military campaign fought between 7 August 1942 and 9 February 1943 on and around the island of Guadalcanal in the Pacific theater of World War II. It was the first major offensive by Allied forces against the Empire of Japan.
Document 5: Doolittle Raid: The Doolittle Raid, also known as the Tokyo Raid, on Saturday, April 18, 1942, was an air raid by the United States on the Japanese capital Tokyo and other places on the island of Honshu during World War II, the first air operation to strike the Japanese Home Islands. It demonstrated that Japan itself was vulnerable to American air attack, served as retaliation for the Japanese attack on Pearl Harbor, and provided an important boost to American morale. The raid was planned and led by Lieutenant Colonel James "Jimmy" Doolittle of the United States Army Air Forces.
Document 6: John W. Mitchell (United States Air Force): John William Mitchell (14 July 1915 – 15 November 1995) was an officer of the United States Air Force, a flying ace and the leader of Operation Vengeance, the mission to shoot down Admiral Isoroku Yamamoto. He served in World War II and the Korean War.
Document 7: Imperial Japanese Navy Aviation Bureau: The Imperial Japanese Navy Aviation Bureau (海軍航空本部 , Kaigun Kōkū Hombu ) of the Ministry of the Navy of Japan was responsible for the development and training of the Imperial Japanese Navy Air Service. In 1941 it was headed by Vice-Admiral Katagiri and was organized as follows:
Document 8: Imperial Japanese Navy Air Service: The Imperial Japanese Navy Air Service (大日本帝國海軍航空隊 , Dai-Nippon Teikoku Kaigun Kōkū-tai ) was the air arm of the Imperial Japanese Navy during World War II. The organization was responsible for the operation of naval aircraft and the conduct of aerial warfare in the Pacific War.
Document 9: Japanese marine paratroopers of World War II: The Imperial Japanese Navy fielded naval paratroopers during World War II. The troops were officially part of the Special Naval Landing Forces (SNLF or "Rikusentai"). They came from the 1st, 2nd and 3rd Yokosuka SNLFs. The 2nd Yokosuka took no part in any airborne operations and became an island defensive base unit. They were under the operational control of the Imperial Japanese Navy Air Service (IJNAS or "Dai-Nippon Teikoku Kaigun Koku Hombu"). "Rikusentai" paratroopers should not be confused with the Imperial Japanese Army paratroopers, known as "Teishin".
Document 10: Battle of Midway: The Battle of Midway was a decisive naval battle in the Pacific Theater of World War II which occurred between 4 and 7 June 1942, only six months after Japan's attack on Pearl Harbor and one month after the Battle of the Coral Sea. The United States Navy under Admirals Chester Nimitz, Frank Jack Fletcher, and Raymond A. Spruance defeated an attacking fleet of the Imperial Japanese Navy under Admirals Isoroku Yamamoto, Chuichi Nagumo, and Nobutake Kondo near Midway Atoll, inflicting devastating damage on the Japanese fleet that proved irreparable. Military historian John Keegan called it "the most stunning and decisive blow in the history of naval warfare."
Document 11: Imperial Japanese Navy: The Imperial Japanese Navy (IJN; Kyūjitai: 大日本帝國海軍 Shinjitai: 大日本帝国海軍 "   " or 日本海軍 "Nippon Kaigun", "Navy of the Greater Japanese Empire") was the navy of the Empire of Japan from 1868 until 1945, when it was dissolved following Japan's defeat and surrender in World War II. It was controlled by the Imperial Japanese Navy General Staff and the Ministry of the Navy, both of which were nominally subordinate to the Emperor of Japan as supreme commander of the army and the navy. The Japan Maritime Self-Defense Force (JMSDF) was formed after the dissolution of the IJN.
Document 12: Operation Vengeance: Operation "Vengeance" was the American military operation to kill Admiral Isoroku Yamamoto of the Imperial Japanese Navy on April 18, 1943, during the Solomon Islands campaign in the Pacific Theater of World War II. Isoroku Yamamoto, commander of the Combined Fleet of the Imperial Japanese Navy, was killed on Bougainville Island when his transport bomber aircraft was shot down by United States Army Air Forces fighter aircraft operating from Kukum Field on Guadalcanal.
Document 13: Imperial Japanese Navy Land Forces: Imperial Japanese Navy Land Forces of World War II were ground combat units consisting of navy personnel organized for offensive operations and for the defense of Japanese naval facilities both overseas and in the Japanese home islands. It consisted of the following:
Document 14: List of territories occupied by Imperial Japan: This is a list of regions occupied or annexed by the Empire of Japan until 1945, the end of World War II in Asia following the surrender of Japan. Control over all territories except the Japanese mainland (Hokkaido, Honshu, Kyushu, Shikoku, and some 6000 small surrounding islands) was renounced by Japan in the Unconditional Surrender after World War II and the Treaty of San Francisco. A number of territories occupied by the United States (the Supreme Commander for the Allied Powers) after 1945 have been returned to Japan, see Japan–United States relations for details. In 2005, there are still a number of disputed territories with Russia (the Kuril Islands dispute), South Korea (the Liancourt Rocks dispute), the People's Republic of China and Taiwan (the Senkaku Islands dispute). See Foreign relations of Japan for details.
Document 15: Surrender of Japan: The surrender of Imperial Japan was announced on August 15 and formally signed on September 2, 1945, bringing the hostilities of World War II to a close. By the end of July 1945, the Imperial Japanese Navy (IJN) was incapable of conducting major operations and an Allied invasion of Japan was imminent. Together with the British Empire and China, the United States called for the unconditional surrender of the Japanese armed forces in the Potsdam Declaration on July 26, 1945—the alternative being "prompt and utter destruction". While publicly stating their intent to fight on to the bitter end, Japan's leaders (the Supreme Council for the Direction of the War, also known as the "Big Six") were privately making entreaties to the still-neutral Soviet Union to mediate peace on terms more favorable to the Japanese. Meanwhile, the Soviets were preparing to attack Japanese forces in Manchuria and Korea (in addition to South Sakhalin and the Kuril Islands) in fulfillment of promises they had secretly made to the United States and the United Kingdom at the Tehran and Yalta Conferences.
ground_truth: Imperial Japanese Navy