Kiyoshi Okamoto was born in the Hawaiian Islands sometime around 1888 or 1889. He claimed to have never graduated from any school, but spent two years at the University of Hawaii where he studied chemistry and engineering. He volunteered for service in World War I but was deferred for reasons never explained to him. He worked as a sugar mill superintendent, a construction engineer and a soil test engineer before moving to San Pedro in Southern California to introduce the papaya. He went broke in the Crash of 1929 and dabbled in newspaper writing, business promotion, and work as a movie extra in Hollywood. Just before the mass expulsion he taught school in Los Angeles and is believed to be the first Nisei to teach in a mainland public high school. He was unmarried and had no children, "not that I know of," he once said.
Okamoto was about 55 at Heart Mountain when he began writing manifestoes against the injustice of the camps, calling himself the "Fair Play Committee of One." He taught Frank Emi about the Constitution and the Bill of Rights, and chaired the Fair Play Committee when it took on the draft issue. He tried to have the camp director removed for incompetence, and a week later was handcuffed and shipped to the Tule Lake Segregation Center. He was brought back to stand trial in Wyoming with the other leaders for conspiracy to counsel draft evasion. He is also credited with being the first Nisei to call for redress for the camps.
After the war Okamoto organized a "Fair Rights Committee" and incorporated in the state of California to again seek redress for the camps. He was known to be prospecting for gold in California. He was last seen gassing up his jeep and heading into the wilderness, and is believed to have died sometime around 1963 at a place unknown.