Yamashiro graduated in 1938 from the design department of Osaka Municipal Polytechnic. He worked in the advertisement department of Hankyu and Tokyo Takashimaya department stores and helped to establish the Japan Design Centre in 1959. In 1952 he had already started a freelance practice, working for Toshiba Electrical Works, Toyota Automobiles, Fuji Steel Mills and others. His awards include the Asahi Advertisement Award, Mainichi Industrial Design Award, ADC Silver and Bronze Awards, Dentsu Advertisement Award. In 1985 he was honoured with the Purple Ribbon Medal and in 1993 with the Fourth Order of Merit, Cordon of the Rising Sun. In 1966 the Japanese Post and Telecommunications Ministry commissioned him to design the stamp for ‘Letter Day’. His works are in the collections of NY MoMA, Stedelijk Museum Amsterdam and Toyama Prefectural Museum of Modern Art. He was a trustee of the Tokyo ADC, a member of Japan Designers Association and a director of Nippon Design Centre.