Shunpei Uto did not take up swimming until he was a teenager, but he quickly demonstrated his proficiency by ascending the Japanese national rankings. He continued swimming as a student at Rikkyo University. At the age of 17 he attended the 1936 Berlin Olympics and won two medals – silver in the 400 metre freestyle and bronze in the 1,500 freestyle. In the same year he was the Japanese champion in the 400 and 1,500 free. World War II hit his fortunes hard and, after the conflict, he was forced to pawn his Olympic medals for food. Uto worked at the Niigata Nippo newspaper company for many years, and then retired to work as a farmer in his home prefecture.