Sadamitsu Fujita was born in Waimea, Hawaii to Japanese immigrants. He attended boarding school in Honolulu, where he adopted the name Neil. He enrolled in Chouinard Art Institute, but his studies were interrupted by the internment of Japanese Americans. In 1942, Executive Order 9066 forced him to move to the Pomona Assembly Center, and later to the Heart Mountain concentration camp in Wyoming. He served as the Heart Mountain Sentinel newspaper's art director and remained in camp until he joined the U.S. Army's 442nd Regimental Combat Team in 1943, a regiment consisting primarily of Japanese American volunteers; It became the most decorated unit in the war. After four years serving in Italy, France, and as a military intelligence infantryman in Japan, Fujita returned to Los Angeles in 1947 and resumed his fine arts studies at Chouinard under the guidance of teachers Millard Sheets and Rex Brandt.
After his studies he joined the prominent Philadelphia ad agency N. W. Ayer & Son. Columbia Records hired him in 1954 to build a design department. Fujita created numerous iconic covers of the period. In 1957, Fujita left Columbia.
In 1963 he joined the public relations firm Ruder & Finn, creating the design division Ruder, Finn & Fujita (later Fujita Design). There he designed the iconic covers for In Cold Blood, The Godfather, and Pigeon Feathers. He taught design at the Philadelphia Museum College of Art, the Pratt Institute, and Parsons School of Design. Fujita died at the age of 89 in Long Island.