Joe M. Nishimoto was born an American citizen to Japanese parents in Fresno, California on February 21, 1919. He was interned like most Japanese-Americans in the wake of the attack on Pearl Harbor. He was at the Jerome War Relocation Center in Arkansas when his brother-in-law arranged for his release and move to Columbus, Ohio.
Nishimoto was living in Columbus when he was drafted into the United States Army on October 4, 1943. He volunteered for service in the all-Nisei (2nd generation Japanese-American) 442nd Regimental Combat Team.