After having graduated from the Woodcraft Department at Tokyo Higher School of Arts and Design (nowadays: Chiba University), he joined architect Bruno Taut’s office in Gunma in 1936. In 1949, Watanabe established his own designing studio. He got famous by the low-cost String Chair in 1952. Watanabe’s Torii Stool and Circular Center Table won the Gold Medal at Triennale di Milano in 1957. Besides interior and furniture design, Watanabe has also designed clocks and watches. His 1972 design, Hibiya Dai-Ichi Life Insurance Company’s pole clock is defined as one of Watanabe’s major works. Watanabe is considered to be one of the pioneers of after-war Japanese design.