Dustbin of History: The Pearl Harbor Spy

The following is an article from Uncle John's Heavy Duty Bathroom Reader.

The Japanese attack on Pearl Harbor on December 7, 1941, remains one of the most infamous events in U.S. history. Yet the spy who played a key role in the sneak attack is a forgotten man, unknown even to many World War II buffs.


On March 27, 1941, a 27-year-old junior diplomat named Tadashi Morimura arrived in Honolulu to take his post as vice-consul at the Japanese consulate. But that was just a cover- "Morimura" was really Takeo Yoshikawa, a Japanese Imperial Navy Intelligence officer. His real mission: to collect information about the American military installations in and around Pearl Harbor.

Relations between the United States and Japan had been strained throughout the 1930s and were now deteriorating rapidly. In 1940, after years of Japanese aggression in China and Southeast Asia, Washington froze Japanese assets in the U.S., cut off exports of oil and war material, and moved the headquarters of the U.S. Navy's Pacific fleet from southern California to Pearl Harbor, bringing it 2,400 miles closer to Japan.

The fleet was in Pearl Harbor to stay. But if Japan wanted its funds unfrozen and the crippling economic embargo lifted, the United States insisted that all Japanese troops had to leave China and Southeast Asia. This was a demand that Japan was unwilling to meet. Instead, it began preparing for war, and by early 1941, the eyes of Japan's military planners had turned to Pearl Harbor.


Yoshikawa had become a spy in a roundabout way. He'd been a promising naval academy graduate, but his career hopes were dashed in 1936 when, just two years after graduation, stomach problems (reportedly brought on by heavy drinking) forced him out of the Japanese Navy. The following year he landed a desk job with Naval Intelligence, where he was put to work learning all that he could about the U.S. Navy.

From 1937 until 1940, Yoshikawa pored over books, magazines, newspapers, brochures, reports filed by Japanese diplomats and intelligence officers from all over the world, and anything else he could find that would give him information about the U.S. Navy. "By 1940 I was the Naval General Staff's acknowledged American expert," he recounted in a 1960 article in the journal Naval Institute Proceedings. "I knew by then every U.S. man-of-war and aircraft by name, hull number, configuration, and technical characteristics. I knew, too, a great deal of information about the U.S. naval bases at Manila, Guam, and Pearl Harbor."


In August 1940, Yoshikawa was ordered to begin preparing for a spy mission in Pearl Harbor. And he was probably surprised by what his superiors told him next: He wasn't going to receive any training in the art of espionage- none at all. He wasn't going to receive any support from Japan's Hawaii spy network, either, because there wasn't one. He would be the only Japanese spy in Hawaii, posing as one Tadashi Morimura, a low-level diplomat assigned to the consulate in Honolulu, and only the consul-general would know his true identity and mission. The job paid $150 a month, plus $600 every six months for expenses. In March, 1941, Yoshikawa arrived in Honolulu.


Now what? Yoshikawa had received very little guidance on how to go about his job, but his worries ended when the consul-general, Nagao Kita, took him to dinner at Shuncho-ro, a Japanese restaurant on a hill overlooking Pearl Harbor. From a private dining room on the second floor of the restaurant, Yoshikawa could see both the Navy base and the nearby Army Air Corps base at Hickam Field laid out below. The Shuncho-ro was the perfect location for studying the flow of ships and aircraft in and out of the harbor, and it even had telescopes. It also happened to be owned by a woman who came from the same prefecture in Japan as Yoshikawa, and she happily made the private dining room (and telescope) available to the up-and-coming young diplomat whenever he requested it.


Yoshikawa quickly discovered that he could accomplish much of his spying without attracting attention, and without even breaking any laws. After all, Pearl Harbor was no isolated military installation; it was part of Honolulu, the Hawaiian Islands' capital city and largest commercial port. Civilians, foreigners, and sightseeing tourists were everywhere. Even if the military had tried to shield Pearl Harbor's operations from prying eyes, it would have been virtually impossible.

Yoshikawa collected a lot of useful information from his observations at the Shuncho-ro, and also by hiking the hillsides that overlooked Pearl Harbor. He could even rent planes at a nearby airport whenever he wanted to take aerial photographs of the ships at anchor. He blended in easily with the large Asian-American population, and he was careful to vary his routine, never visiting any one place too frequently, and never staying any longer than necessary. Sometimes he posed as a laborer; other times he put on a loud Hawaiian shirt and masqueraded as a tourist. When he felt conspicuous traveling alone on, say, a visit to a military air show or plane or boat ride around the harbor, he'd take one of the geisha girls who worked at the Shuncho-ro or one of the female consular staff on a "date", always being careful not to reveal his true identity or mission to his companion. An experienced long-distance swimmer, Yoshikawa also made many swims around the harbor to study its defenses. By breathing through a reed, he could swim underwater when needed to avoid detection.


After a long day of spying on land or in the water, Yoshikawa passed many an evening picking up hitchhiking U.S. soldiers or buying drinks for servicemen in bars, prying as much information out of them as he could without arousing suspicion. (Soldiers who were tight-lipped around male foreigners often happily spilled the beans to the geishas at Shuncho-ro, so Yoshikawa made sure to question them, too.) After the restaurants and bars closed, he would pose as a drunken bum and scour the dumpsters outside of military installations for any documents he could get his hands on.

Yoshikawa rarely took photographs, and he never drew diagrams or wrote anything down while making his rounds. He never carried a notepad; Instead, he relied on his photographic memory to record every detail -locations and numbers of ships and aircraft, the timing of their arrivals and departures, the depth of water in different parts of the harbor, everything- so that if he were stopped and questioned, there would be no evidence on him that suggested he was a spy. He never even carried binoculars for fear they would call too much attention to him or arouse suspicion.


If Japan had planned its attack on Pearl Harbor without the data Yoshikawa gathered, it's quite possible it would have been a mere glancing blow, one that damaged the Pacific Fleet but did not knock it out of commission. But the information Yoshikawa provided was devastating:

* When he reported that air patrols rarely watched the waters north of Oahu (where the seas were thought to be too treacherous for an enemy to mount an attack), the Japanese military planners decided to attack from that direction.

* When he told them the water in the harbor wasn't deep enough for ordinary torpedoes, they devised a torpedo with special fins that would work in shallow water.

* When Yoshikawa told them that the ships along "Battleship Row" were moored in pairs to protect the inboard ships from torpedo attacks, the planners decided to attack those ships with armor-piercing bombs dropped from dive-bombers.

* When he reported that ships commonly left the harbor for maneuvers on Monday and returned to the port at the end of the week, the planners set their attack for the weekend.

* When they asked Yoshikawa which day of the weekend the most ships were likely to be in the harbor, he replied simply: "Sunday."

Continue reading this two-part story.


The article above was reprinted with permission from the Bathroom Institute's newest book, Uncle John's Heavy Duty Bathroom Reader.

Since 1988, the Bathroom Reader Institute had published a series of popular books containing irresistible bits of trivia and obscure yet fascinating facts.

If you like Neatorama, you'll love the Bathroom Reader Institute's books - go ahead and check 'em out!

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Well, the Japanese may have surrendered but they pretty much ''invaded'' Honolulu anyway. It's like Little Japan.

The Memorial is wonderful, though. If only the tourists would shush like they are asked to when they take you out to the actual memorial site. They keep jabbering and it's aggravating. So disrespectful.
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