Nishimura attended naval artillery and torpedo school from 1914 to 1915, and then was assigned to the destroyer Yugiri, the armored cruiser Yakumo, and the battlecruiser Haruna.

As a lieutenant from 1917, Nishimura specialized in navigation, and served as chief navigator on a large number of vessels, including the corvette Yamato, the destroyers Kawakaze, Tanikaze, Yura, and Sunosaki, the light cruisers Kitakami and Ōi, and the battleship Hizen.

In 1944, he was named the commander of the Southern Force[3] in Operation Sho-Go, aimed at a final and decisive naval battle against the United States Navy in the Philippines.

Nishimura's Force "C" consisted of the battleships Fusō and Yamashiro, the heavy cruiser Mogami, and the destroyers Shigure, Michishio, Asagumo, and Yamagumo.

Seventh Fleet under Rear Admiral Jesse Oldendorf, which consisted of six battleships, eight cruisers, 29 destroyers, and 39 motor torpedo boats.