Katsui Mitsuo was born in Tokyo in 1931 and graduated from Tokyo Education University in 1955. In 1956, he joined Ajinomoto Co., Ltd., but began working as a freelance designer in 1961. Throughout his career, he received numerous awards, including the JAAC Award in 1958, the Mainichi Industrial Design Award in 1965, and the Tokyo ADC Membership Prize in 1972.