After completing naval artillery and basic torpedo training, he was assigned to the battleship Aki, and was promoted to sub-lieutenant on 1 December 1910.

He subsequently served in a number of staff positions, including that of naval attaché to Germany from August 1922 to September 1924.

Nomura visited Germany again during most of 1929, and was part of the Japanese delegation to the London Naval Treaty talks.

During his time in Germany, he was active in attempting to procure the latest in military technology for Japan, especially developments pertaining to submarines and aircraft.

[4] In the final stages of the Pacific War, he served as commander in chief of the Yokosuka Naval District and of the Maritime Escort Fleet.

Nomura was the center of a controversy in 1971, when he headed a group of Japanese war veterans in an attempt to recover the destroyer Yukikaze after it had been sold for scrap by the Republic of China Navy.