Kenpeitai

The , also known as Kempeitai, was the military police arm of the Imperial Japanese Army from 1881 to 1945. It was both a conventional military police and a secret police force. In Japanese-occupied territories, the kenpeitai also arrested or killed those who were suspected of being anti-Japanese. While it was institutionally part of the army, the Kenpeitai also discharged the functions of the military police for the Imperial Japanese Navy under the direction of the Admiralty Minister (although the IJN had its own much smaller Tokkeitai), those of the executive police under the direction of the Home Minister and those of the judicial police under the direction of the Justice Minister. A member of the corps was called a "kenpei" (憲兵).
History.
The Kenpeitai was established in 1881 by a decree called the , figuratively "articles concerning gendarmes". Its model was the National Gendarmerie of France. Details of the Kenpeitai's military, executive, and judicial police functions were defined by the "Kenpei Rei" of 1898, which was amended twenty-six times before Japan's defeat in August 1945.
The force initially consisted of 349 men. The enforcement of the new conscription legislation was an important part of their duty, due to resistance from peasant families. The Kenpeitai's general affairs branch was in charge of the force's policy, personnel management, internal discipline, as well as communication with the Ministries of the Admiralty, the Interior, and Justice. The operation branch was in charge of the distribution of military police units within the army, general public security and intelligence.
In 1907, the Kenpeitai was ordered to Korea where its main duty was legally defined as "preserving the peace", although it also functioned as a military police for the Japanese army stationed there. This status remained basically unchanged after Japan's annexation of Korea in 1910.
The Kenpeitai maintained public order within Japan under the direction of the Interior Minister, and in the occupied territories under the direction of the Minister of War. Japan also had a civilian secret police force, "Tokkō", which was the Japanese acronym of "Tokubetsu Kōtō Keisatsu" ("Special Higher Police") part of the Interior Ministry. However, the Kenpeitai had a "Tokkō" branch of its own, and through it discharged the functions of a secret police.
When the Kenpeitai arrested a civilian under the direction of the Justice Minister, the arrested person was nominally subject to civilian judicial proceedings.
The Kenpeitai's brutality was particularly notorious in Korea and the other occupied territories. The Kenpeitai were also abhorred in Japan's mainland as well, especially during World War II when Prime Minister Hideki Tojo, formerly the Commander of the Kenpeitai of the Japanese Army in Manchuria from 1935 to 1937, used the Kenpeitai extensively to make sure that everyone was loyal to the war.
According to United States Army TM-E 30-480, there were over 36,000 regular members of the Kenpeitai at the end of the war; this did not include the many ethnic "auxiliaries". As many foreign territories fell under the Japanese military occupation during the 1930s and the early 1940s, the Kenpeitai recruited a large number of locals in those territories. Taiwanese and Koreans were used extensively as auxiliaries to police the newly occupied territories in Southeast Asia, although the Kenpeitai recruited French Indochinese (especially, from among the Cao Dai religious sect), Malays and others. The Kenpeitai may have trained Trình Minh Thế, a Vietnamese nationalist and anti-Viet Minh military leader.
The Kenpeitai was disarmed and disbanded after the Japanese surrender in August 1945.
Today, the post-war Self-Defense Forces' internal police is called "Keimutai" (警務隊). Each individual member is called "Keimukan". Modelled on the Military Police in the United States and other western armed forces, they have no jurisdiction over civilians.
Axis powers.
In the 1920s and the 1930s, the Kenpeitai forged various connections with certain prewar European intelligence services. Later, when Japan signed the Tripartite Pact, Japan formed formal links with the intelligence units, now under German and Italian fascists, known as the German Abwehr and the Italian Servizio Informazioni Militare. The army and the navy of Japan contacted their corresponding Wehrmacht intelligence units, Schutzstaffel (SS) or Kriegsmarine, about information on Europe and vice versa. Europe and Japan realized the benefits of the exchanges. For example, the Japanese sent data about Soviet forces in the Far East and in Operation Barbarossa from the Japanese embassy. Admiral Canaris offered aid in respect to the neutrality of Portugal in Timor.
One important contact point was at the Penang submarine base, in occupied British Malaya. The base served Axis submarine forces (Italian Regia Marina, German Kriegsmarine and the Dai Nippon Teikoku Kaigun, or Imperial Japanese Navy). At regular intervals, technological and information exchanges occurred there. While these were available to them, Axis forces used the bases in Italian East Africa, the Vichy France colony of Madagascar and some officially neutral places like Portuguese India.
Human rights abuses.
The Kenpeitai ran extensive criminal and collaborationist networks, extorting vast amounts of money from businesses and civilians wherever they operated. They also ran the Allied prisoner of war system, which often treated captives with extreme brutality. Many of the abuses were documented in Japanese war crimes trials, such as those committed by the Kempeitai East District Branch in Singapore.
The Kenpeitai also carried out revenge attacks against prisoners and civilians. For example, after Colonel Doolittle's raid on Tokyo in 1942, the Kenpeitai carried out reprisals against thousands of Chinese civilians and captured airmen, or in 1943 the Double Tenth massacre which was in response to an Allied raid on Singapore Harbour. They also supplied 600 men, women and children per year for Unit 731, where infamous human experiments were conducted.
Organization.
The Kenpeitai maintained a headquarters in each relevant Area Army, commanded by a Shosho (Major General) with a Taisa (Colonel) as Executive Officer and comprising two or three field offices, commanded by a Chusa (Lieutenant Colonel) and with a Shosa (Major) as executive officer and each with approximately 375 personnel.
The field office in turn was divided into 65-man sections called 'buntai'. Each was commanded by a Tai-i (Captain) with a Chu-i (1st Lieutenant) as his Executive Officer and had 65 other troops. The buntai were further divided into detachments called "bunkentai", commanded by a Sho-i (2nd Lieutenant) with a Junshikan (Warrant Officer) as Executive Officer and 20 other troops. Each detachment contained three squads: a police squad or "keimu han",
an administration squad or "naikin han", and a special duties squad or "Tokumu han".
Kenpeitai Auxiliary units consisting of regional ethnic forces were organized in occupied areas. These troops supplemented the Kenpeitai and were considered part of the organization but were limited to the rank of Socho (Sergeant Major).
By 1937 the Kenpeitai had 315 officers and 6,000 enlisted. These were the members of the known, public forces. The Allies estimated that by the end of World War II, there were at least 7,500 members of the Kenpeitai.
Active units.
The Kenpeitai operated commands on the Japanese mainland and throughout all occupied and captured overseas territories during the Pacific War. The external units operating outside Japan were: 
Wartime mission.
The Kenpeitai was responsible for the following:
By 1944, despite the obvious tide of war, the Kenpeitai were arresting people for antiwar sentiment and defeatism.
Uniform.
Personnel wore either the standard M1938 field uniform or the cavalry uniform with high black leather boots. Civilian clothes were also authorized but badges of rank or the Japanese Imperial chrysanthemum were worn under the jacket lapel. Uniformed personnel also wore a black chevron on their uniforms and a white armband on the left arm with the characters "ken" (憲, "law") and "hei" (兵, "soldier"), together read as "kenpei" or "kempei," which translates to "military policeman". 
A full dress uniform comprising a red kepi, gold and red waist sash, dark blue tunic and trousers with black facings was authorized for officers of the Kenpeitai to wear on ceremonial occasions until 1942. Rank insignia comprised gold Austrian knots and epaulettes.
Personnel were armed with either a cavalry sabre and pistol for officers and a pistol and bayonet for enlisted men. Junior NCOs carried a "shinai" (竹刀, "bamboo kendo sword") especially when dealing with prisoners.