Satō was born as Sute Yamaoka in the city of Nihonmatsu, Fukushima, on 15 October 1902. She was descended from former Nihonmatsu clan members, with her great-uncle, Eiji Yamaoka (山岡栄治) being well-known in Aizuwakamatsu as a gallant soldier who fought in the 1868-69 Boshin War (戊辰戦争). A stone monument has been erected there to commemorate him.
Satō was married in 1925 to a police officer, and the couple lived in several towns across Fukushima, including Aizumisato and Kaneyama, eventually settling in Aizuwakamatsu. It was there that she moved into a nursing home in 2005.
At the age of 105, Satō was hospitalised with pneumonia, the first major illness of her life, which she soon recovered from. Her grandson claimed that she had a ‘positive and calm personality’ and that ‘avoiding stress’ was the secret to his grandmother’s longevity.
In 2014, on her 112th birthday, Satō’s eldest son was still living. At the time, she had 14 grandchildren and over 20 great and great-great grandchildren. She died on 29 May 2015 at the age of 112 years, 226 days.