Imperial Japanese Army The Imperial Japanese Army , often shortened to the Imperial Army or Japanese Army , was the army of Japan and the Japanese Empire during its period of expansion in the 1930s and during World War II . Its aviation force was the Imperial Army Air Fleet . ( PROSE : " The Shadow of Weng - Chiang " ) Its general s also ran the Japanese government . ( PROSE : " Endgame " ) History . Pre - war expansion . Between 1931 and 1932 , the Japanese invaded the Chinese province of Manchuria . They established the puppet state of Manchukuo occupied and managed by the Kwantung Army , who forced the local peasants into slave labour and committed many atrocities in the region to deter escape attempts . ( PROSE : " Log 384 " ) Kwantung Army Intelligence set up their headquarters in Hsinking . Major Ryuji Matsu ' s men set up operations in the requisitioned Dazheng Hall in the Imperial Palace in Mukden , hanging the flag of the blood - red sun emblem from every flagpole . ( PROSE : " The Shadow of Weng - Chiang " ) In 1932 , Japanese troops were deployed onto the streets of Shanghai and clashed against the Chinese . Ishiguro Takashi was an officer during the confrontation , while Major Matsu recruited Sung - Chi Li as a double agent . ( PROSE : " The Shadow of Weng - Chiang " ) In 1933 , the young military scientist Ishii Shiro headed research initiatives in Manchukuo intended to develop weapons for biological warfare . On a mission to rescue Mai Ling from the Zhong Ma Fortress , the Seventh Doctor and Edward Grainger encountered and were briefly captured and experimented on by Kwantung Army guard s . ( PROSE : " Log 384 " ) After the invasion of Manchuria , the Army split into two factions : the militant Kodo Ha , which favoured action against the Soviet Union , and the more cautious but still expansionist Tosei Ha , which favoured action against China . In February 1936 , the Sakura Kai influenced the First Infantry Division into launching a military revolt in Tokyo in support of the Kodo Ha . Despite the murder of many politician s , the revolt was suppressed , leaving the Tosei Ha , at least nominally , in charge of the Army . ( PROSE : " The Shadow of Weng - Chiang " ) Later that year , Japanese soldiers continued to fight against the Chinese . ( PROSE : " Doctor Who and the War Games " ) War with China . In July 1937 , the Army engineered a fight between the Chinese at Marco Polo Bridge in order to justify further expansion into China . This marked the beginning of World War II in Asia . By August , the Japanese Twelfth Army had moved into Shangdong province and controlled everything north of Tai ' an and the mountain of T ' ai Shan . However , the priority of the Japanese at this stage of was to consolidate Manchuria rather than push hard into China . When the Chinese Nationalist diverted their forces to offset the Communists near Mongolia , Japanese activities in the region became uneventful and they encountered little resistance Ishiguro Takashi , who lost his brothers in the Tokyo revolt , deserted the Army and eventually fled to Shanghai . There he worked as a nightclub owner named Woo and a vigilante named Yan Cheh , seeking to create a united front to resist the Kwantung Army once they moved towards Shanghai . Hsien - Ko and Mr Sin had a number of fatal encounters with the Japanese troops in the occupied territories of China . The Japanese eventually moved into Shanghai . ( PROSE : " The Shadow of Weng - Chiang " ) Global war . On Sunday , 7 December 1941 , the Japanese Air Fleet attacked Pearl Harbour , bringing the United States of America into the war . ( PROSE : " Only Connect " ) Shortly after , they engaged the Americans in the Philippines . ( PROSE : " Happily Ever After Is a High - Risk Strategy " ) The Pacific island s between Japan and the US were occupied by thousands of Japanese troops who were prepared to die rather than surrender . American advisers told the President that only a direct order from the Japanese Emperor could convince these soldiers to surrender . ( PROSE : " Endgame " ) In February 1942 , the Army attacked the British Empire ' s Asian colonies and advanced into Singapore . British troops awaiting evacuation from the island of Kenga were terrorised by Japanese raiding parties . ( AUDIO : " The Forsaken " ) The Army surrendered to the Americans in 1945 after the atomic bomb ings of Hiroshima and Nagasaki . The Army ' s ferocity and fanaticism convinced the Allies that the bombings were necessary in order to shorten the war . ( PROSE : " Endgame " )