Itaya was born in Nakahara Village in Miyaki District, Saga Prefecture on 20 August 1911, the second son of a farmer.

His older brother was Shigeru Itaya [ja] who would also go on to serve in the Japanese Imperial Navy as a naval aviator and squadron commander participating in the Attack on Pearl Harbor and the Battle of Midway until he was killed in action over the northern Kuril Islands as a result of friendly fire on 24 July 1944.

[1][2] After his graduation he was promoted to ensign and later posted to China to where he served with the Shanghai Special Naval Landing Force.

[11] The next year he was briefly reassigned as the weapons officer aboard the destroyer Shigure before attending the Naval Gunnery School [ja],[12] after graduating Itaya was assigned as the weapons officer aboard the destroyer Asashio.

[13] In 1941 Itaya served on the battleship Nagato[14] before being transferred in 1942 to the light cruiser Natori as the ship's weapons officer where he was promoted to lieutenant commander.

After his retirement Itaya was an advisor to Mitsubishi Heavy Industries and in 1981 was awarded the Order of the Sacred Treasure, Second Class for his service in the JMSDF.