was an historian

Historian

A historian is a person who studies and writes about the past and is regarded as an authority on it. Historians are concerned with the continuous, methodical narrative and research of past events as relating to the human race; as well as the study of all history in time. If the individual is...

 and lieutenant general

Lieutenant General

Lieutenant General is a military rank used in many countries. The rank traces its origins to the Middle Ages where the title of Lieutenant General was held by the second in command on the battlefield, who was normally subordinate to a Captain General....

 in the Japan Air Self-Defense Force

Japan Air Self-Defense Force

The , or JASDF, is the aviation branch of the Japan Self-Defense Forces responsible for the defense of Japanese airspace and other aerospace operations. The JASDF carries out combat air patrols around Japan, while also maintaining an extensive network of ground and air early warning radar systems...

.

Okumiya graduated from 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...

 and served as a naval aviator in the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

. In 1937, he participated in the attack on the USS Panay

Panay incident

The USS Panay Incident was a Japanese attack on the American gunboat while she was anchored in the Yangtze River outside Nanking , China on December 12, 1937. Japan and the United States were not at war at the time. The Japanese claimed that they did not see the American flags painted on the deck...

. Okumiya served throughout World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, including on the Japanese aircraft carrier Ryūjō

Japanese aircraft carrier Ryujo

Ryūjō was a light aircraft carrier of the Imperial Japanese Navy. She was laid down by Mitsubishi at Yokohama in 1929, launched in 1931 and commissioned on 9 May 1933. Her final design resulted in a top-heavy unstable vessel and within a year she was back at Kure Naval Yard for modification...

 and with the 2nd Air Fleet of the Imperial Japanese Navy, finishing the war as a Commander

Commander

Commander is a naval rank which is also sometimes used as a military title depending on the individual customs of a given military service. Commander is also used as a rank or title in some organizations outside of the armed forces, particularly in police and law enforcement.-Commander as a naval...

. At the end of the war, Okumiya was interrogated by Allied intelligence officers.

Following the occupation of Japan, he continued serving in the Japan Air Self-Defense Force

Japan Air Self-Defense Force

The , or JASDF, is the aviation branch of the Japan Self-Defense Forces responsible for the defense of Japanese airspace and other aerospace operations. The JASDF carries out combat air patrols around Japan, while also maintaining an extensive network of ground and air early warning radar systems...

.

Okumiya wrote extensively on Japan's role in World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. He co-wrote, with Jiro Horikoshi and Martin Caidin, an historical account of the Japanese ZERO fighter, titled ZERO! The book was published in 1956.