The son of a police officer, he was born on Taiwan in 1942. The family fled back to Japan at the end of the War and encountered a number of hardships, including living in a stable. He was educated at Doshisha University in Kyoto, and moved to the United States in 1968. His first job was at the New York branch of the official trade agency, JETRO, from April 1969; meanwhile he was translating art books and catalogues anonymously for Weatherhill. The first work to appear under his own name was a small collection of poems by Princess Shikishi. He attracted attention in the Japanese press with the anthology Ten Japanese Poets (1973) and his translations were soon published by the Chicago Review.

Most of Sato's translations are from Japanese into English, but he has also translated verse by John Ashbery into Japanese. He has also provided translations of primary sources on the subject of the samurai tradition in feudal Japan. He is currently translating Inose Naoki's biography of Yukio Mishima.

Sato was a president of the Haiku Society of America from 1979 to 1981 (and honorary curator in 2006-7). He was a professor of Japanese literature at St. Andrews Presbyterian College in North Carolina from 1985 to 1991, and then director of research and planning at JETRO New York. Since 1998 he has been an adjunct at the University of Massachusetts Amherst. He lives in New York City.