Eighty years ago, the United States was still at relative peace.

In Europe, Britain was hanging on for life while France and most of the other occupied nations were adjusting to life under the heel of the Nazi warlords. In the Far East, Japan was beginning to feel the pressure of the sanctions imposed by America and others. It was only a matter of time before the nations involved would clash openly but much work needed to be done first by the Japanese.

One action that was set in motion was to gather more intelligence about the American bases at Pearl Harbor and around Oahu. The island was filled with many nationalities including Japanese. But despite American fears and concerns, it would not be an Island person who would gather the most critical information. Today’s story is part one of a two part series abut the principal spy and his work.

Takeo Yoshikawa (吉川 猛夫, Yoshikawa Takeo, March 7, 1912 – February 20, 1993) was a Japanese spy in Hawaii before the attack on Pearl Harbor on December 7, 1941.

A 1933 graduate of the Imperial Japanese Naval Academy at Etajima (graduating at the top of his class), Yoshikawa served briefly at sea aboard the armored cruiser Asama as well as submarines. He had begun training as a naval pilot near the end of 1934 when a severe stomach ailment prevented him from completing his training. He was subsequently discharged from the Imperial Japanese Navy in 1936. As a result, he briefly contemplated suicide.

A year later he began a career in naval intelligence, being assigned to Navy Headquarters in Tokyo. He became an expert in the U.S. Navy, perusing every source he could possibly get his hands on. While on intelligence duty he intercepted a shortwave radio message in plain English that 17 troop transports were en route to England, having cleared the port of Freetown, Sierra Leone. He passed this information to the German Embassy, and many of the ships were destroyed as a result. Yoshikawa subsequently received a personal letter of thanks from Adolf Hitler. In 1940 he became a junior diplomat after passing the Foreign Ministry English examinations.

A spy in Hawaii

Because of his expertise on the U.S. Navy, Yoshikawa was sent to Hawaii posing as a vice-consul named Tadashi Morimura (森村 正 Morimura Tadashi), arriving on March 27, 1941, with Nagao Kita (喜多 長雄 Kita Nagao), the new Japanese Consul-General aboard the liner Nitta Maru. He rented a second-story apartment that overlooked Pearl Harbor and would often wander around the island of Oahu, taking notes on fleet movements and security measures. He rented small airplanes at John Rodgers Airport and flew around, observing U.S. installations; he also dove under the harbor using a hollow reed as a breathing device. He gathered information by taking the Navy’s own harbor tugboat and listening to local gossip. He worked closely with German Abwehr agent Bernard Kuehn, as well as another former Etajima graduate, Kokichi Seki (関 興吉 Seki Kō’kichi), an untrained spy who served as the consulate’s treasurer.

According to Yoshikawa, although some 160,000 persons of Japanese ancestry lived in Hawaii at that time, he never tried to make use of this resource in his espionage activities. He and Seki agreed that, while Hawaii should be the “easiest place” to carry out such work in view of the large Japanese population, both looked upon the locals with disdain. “[T]hose men of influence and character who might have assisted me in my secret mission were unanimously uncooperative….”

Although he had no knowledge of a planned attack on Naval Station Pearl Harbor, Yoshikawa assumed that the intelligence would help prepare for such an eventuality and worked tirelessly to that end. His reports were transmitted by the Japanese consulate in PURPLE code to the Foreign Ministry, which passed them on to the Navy. Although the code had been broken by Allied codebreakers and messages to and from Tokyo were intercepted and decrypted, communications between Tokyo and the consulate were considered low-priority because they contained so many messages that were entirely commercial in nature. However, one such message addressed to Kita (but actually to Yoshikawa) and sent on September 24, 1941, should have received more attention. It divided Pearl Harbor into five distinct zones and requested that the location and number of warships be indicated on a “plot” (i.e., grid) of the harbor. However, due to delays caused by staff shortages and other priorities the message was not decrypted and distributed until mid-October, and then dismissed as being of little consequence. However, it was the reports that he sent twice a week based on this request that enabled Admiral Isoroku Yamamoto to finalize his plan for the attack.

When he heard the “East wind, rain” code phrase on the short wave radio bringing the news from Tokyo to signal that an attack against the United States was to proceed, Yoshikawa destroyed all evidence of his activities.

When the FBI picked him up on the day of the attack, there was no incriminating evidence of his espionage. He eventually returned to Japan in August 1942 in a diplomat prisoner exchange. It was not known for some time that he was the chief Japanese agent in Hawaii.

Return to Japan and later life

Yoshikawa continued to work for naval intelligence during the remainder of the war. When the war ended and Japan was occupied by U.S. forces, he went into hiding (disguised as a Buddhist monk) for fear of being prosecuted for his role in the Pearl Harbor attack. He returned to his wife (whom he married shortly after his return from the U.S.) when the occupation ended.

More about his story tomorrow

What is most interesting to me about his work is that he does not appear to have placed much emphasis on the submarine base other than notes of general interest. Its interesting because he himself was a submariner before health concerns took him away from the seagoing services.

Mister Mac