Tommy Tomeki Nishioka was born in Pahala, Hawaii in 1921 to immigrants from Kumamoto, Japan. His father worked as a tree planter while his mom worked in the plantation fields. After graduating from Pahala High School in 1940, he worked for the Hawaiian Agricultural Company as a Chemist Assistant.
He volunteered in March 1943 and joined the 442nd Regimental Combat Team. Due to the heavy casualties in the 100th Infantry Battalion, he was sent as a replacement and served with A Company.
Upon his discharge, Nishioka worked for the Pearl Harbor Naval Shipyard as a Statistical Assistant. He received the prestigious Zero Defect Plaque, an award given after a review of candidates from the entire Shipyard. Nishioka was promoted to Budget Analyst and retired in 1980.