The Kempeitai (憲兵隊, Kenpeitai?, "Military Police Corps") was the military police arm of the Imperial Japanese Army from 1881 to 1945. It was not an English-style military police, but a German Style secret police like the S.S.. Therefore, while it was institutionally part of the Imperial Japanese Army, it 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 Interior Minister, and those of the judicial police under the direction of the Justice Minister. A member of the corps was called a kempei.
Read more about Kempeitai: History, Japanese Secret Services and The Axis Powers, Organization, Wartime Mission, Uniform, Japanese Secret Services and Conquest Planning