"Operational History of Japanese Naval Communications"

After WWII, the Japanese Government conducted war records investigation under instructions from the GHQ (the General Headquarters of the Supreme Commander for the Allied Powers). After the War Ministry and the General Staff were dissolved, the work was conducted under the supervision of the Demobilization Bureau. Records were compiled by former officers who had been on duty during the war. An English version was distributed as
Operational History of Naval Communications: December 1941-August 1945. Japanese Monograph No.118 (Department of the Army: Office of the Chief of Military History, 1953) (pdf)
I learned of this by a citation in Chapter 17 of David Kahn, The Codebreakers. When I bought its paper reprint twenty years ago, I did not have access to the Japanese original. Now, the original (海軍作戦通信使), prepared by the Second Demobilization Bureau and dated March 1949, can be found at JACAR (Ref: C19010076600).
An edition by the Service School of the Safety Security Force (警備隊術科学校), dated 1953, is also available in pdf on Akio Tsutsumi's website ().