Yoshiko Naitō was born in Yamanashi City, Yamanashi Prefecture, Japan, on 10 February 1912, as the second of four siblings. During her school years at an all-girls’ school, she was an excellent student who loved studying. Following her graduation, she spent several years teaching Japanese dressmaking to local girls in her community until her marriage. At the age of 21, she married a seal engraver, four years her senior, and the couple had five children.

From her youth, she had numerous hobbies and interests. These included a passion for international travel, pilgrimages to temples across Japan, reading books, and tending to a vegetable garden, a practice she carried on until the age of 95 when she suffered a subarachnoid hemorrhage. Her final overseas trip took place at the age of 93. Between her 60s and 90s, she visited about 20 countries. She made regular pilgrimages to both Shikoku and Kanto, displaying a profound devotion to Buddhism. In her daily life, she remained physically active, walking the approximately 2.5-kilometer distance to her vegetable garden daily. She was reading newspapers daily, borrowing a minimum of five books monthly from the library, and participating in an elderly educational institution known as “Kangakuin” (Japanese: 勧学院).

Her family attributed her longevity to a combination of factors, including her genetic predisposition for a long life, her commitment to physical activity, and her nutritious diet. As of October 2023, her younger brother was 101, and her younger sister was 98 years old.