The Tokkeitai (特警隊, short for 特別警察隊 Tokubetsu Keisatsutai, "Special Police Corps"; the Naval Secret Police) was the Imperial Japanese Navy's military police, they were equivalent to the Imperial Japanese Army's Kempeitai. They were also the smallest military police service.
The original Tokkeitai was known as the General Affairs Section and concerned itself with police and personnel work within the Navy: personnel, discipline and records. It took a more active role, partly to keep the Kempeitai and Army from meddling in Navy affairs. Smaller and more low-key than its rival, it was no less brutal. It was especially active in the areas of the South Pacific, the Naval Control Area, as well as maintaining a presence as pervasive as the Kempeitai had. It had the same 'commissar' roles, in relation to exterior enemies or suspicious persons, and watching inside units for possible defectors or traitors, under the security doctrine of "Kikosaku".
Attached to Navy units, they served as Colonial police in some occupied Pacific areas. Later accusations of war crimes were made against them in that role for such acts as coercion of women from Indonesia, Indochina and China into sexual slavery.
In addition to its police responsibilities the Tokkeitai was the operative branch of the Secret Service Branch of the Imperial Japanese Navy (Information Office (情報局, Jōhō-kyoku) which was responsible for recovering and analyzing information and for the execution of undercover operations. Its members also provided local security near naval bases. In the final weeks of the Pacific War, they were amongst the security units prepared for combat against the proposed Allied invasion of Japan.