Born in Hana, Maui County, Hawaii, United States, to parents of Japanese lineage on 11 February 1902 according to the United States Social Security Death Index, Mori spent her childhood on a small sugarcane farm established on leased land by her parents. She remembered seeing a car for the first time at age seven, being surprised at its coldness (as she was accustomed to riding on horses, which were warm), and thinking "It moves?"
Mori, her husband, and their son lived as a family in Hawaii for most of their life, with granddaughter Joyce Lampert describing it as "difficult but rewarding".
Mori had to raise her son with difficulty with food rations when her husband, Tenran Mori, legally a Japanese citizen, was recalled less than twenty years into their marriage during the Second World War to assist in the war effort. Seventeen years after the war, the pair founded a temple in Honolulu, which to this day bears a bust of Mori's husband on its grounds.
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| Mori with granddaughter Joyce Lampert on 10 January 2012 |
Mori's family stated that she had been born on 10 January 1902, and that the doctor responsible for her birth had failed to register it until 10 February of the same year. Although she celebrated her presumed 110th birthday with her family in January 2012, she died on 1 February 2012, just over three weeks later. Although the Social Security Administration has been known to turn up erroneous cases in the past, its take on her birthdate of 11 February 1902, the most conservative, would mean Mori had lived for a total of 109 years and 355 days. Had her date of birth indeed been 10 January, she would have lived 110 years 22 days, thus making her a true supercentenarian by three weeks.