was a Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese spy

SPY

SPY is a three-letter acronym that may refer to:* SPY , ticker symbol for Standard & Poor's Depositary Receipts* SPY , a satirical monthly, trademarked all-caps* SPY , airport code for San Pédro, Côte d'Ivoire...

 in Hawaii

Hawaii

Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

 before the attack on Pearl Harbor

Attack on Pearl Harbor

The attack on Pearl Harbor was a surprise military strike conducted by the Imperial Japanese Navy against the United States naval base at Pearl Harbor, Hawaii, on the morning of December 7, 1941...

 on December 7, 1941.
A 1933 graduate of the Imperial Japanese Naval Academy

Imperial Japanese Naval Academy

The was a school established to train officers for the Imperial Japanese Navy. It originally located in Nagasaki, moved to Yokohama in 1866, and was relocated to Tsukiji, Tokyo in 1869. It moved to Etajima, Hiroshima in 1888...

 at Etajima

Etajima

Etajima is an island in Hiroshima Bay located in southwestern Hiroshima Prefecture.From the city of Hiroshima the island is about 7km out at sea. The island is about 6km from the city of Kure. It is connected to Kure by two bridges....

 (graduating at the top of his class), Yoshikawa served briefly at sea aboard the armored cruiser

Armored cruiser

The armored cruiser was a type of warship of the late 19th and early 20th centuries. Like other types of cruiser, the armored cruiser was a long-range, independent warship, capable of defeating any ship apart from a battleship, and fast enough to outrun any battleships it encountered.The first...

 Asama

Japanese cruiser Asama

was the lead ship of an early class of armored cruisers of the Imperial Japanese Navy. The ship was named after Mount Asama, located north of Tokyo. Its sister ship was the .- Background :...

as well as submarine

Submarine

A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...

s and 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.