Kuniaki Koiso (小磯 国昭 Koiso Kuniaki, March 22, 1880–November 3, 1950) was the 41st Prime Minister of Japan from July 22, 1944 to April 7, 1945.
Koiso was born in Tochigi Prefecture in 1880. A career soldier, Koiso graduated from Japan’s Army Academy in 1900 and went on to attend the nation’s War College. He eventually attained the rank of general. Koiso’s career took off rapidly in the 1920s and 1930s, when he held a variety of prominent military and governmental positions. These positions included Chief of the Material Mobilization Bureau of the Ministry of War (1929-1930), Chief of the Military Affairs Bureau of the Ministry of War (1930-1931), Vice Minister of War (1932), Chief of the Kwantung Army in occupied Manchuria (1932-1934), and Minister of Overseas Affairs (1939, 1940). Koiso was Governor-General of Korea from 1942 to 1944, where he gained the nickname “The Tiger of Korea” for his harsh administration.
In 1944, with the downfall of Hideki Tojo’s government, Koiso was chosen to serve as the new Prime Minister of Japan despite strong competition from senior army officials. During his term in office, Japanese forces faced multiple defeats at the hands of the United States Military. For a time, Koiso considered making peace with the Allies, but he could not find a solution that would appease either the Japanese military or the Americans. Left with little choice but to continue the war effort, Koiso eventually tried to extend his power over the army by attempting to assume the position of War Minister, but failed to do so because he was on the list of inactive generals. Koiso eventually resigned in 1945 when U.S. forces captured Okinawa. After the war, he was captured by the Allies and tried by the International Military Tribunal for the Far East for war crimes. Upon conviction, he was given a sentence of life imprisonment. Koiso died in 1950 while serving his sentence.