Fumi Seino was born in Ōdate, Akita Prefecture, Japan, on 2 February 1914, as the fifth of nine children. Her sister lived to be 102 years old.

After graduating from elementary school, she trained as a maid, performing housework and babysitting at a mansion in Ōdate. When she was around 22 years old, she married a sculptor who specialized in Buddhist statues and similar works, and the couple raised four daughters. While raising her children, Seino worked as a chick seller at her sister’s poultry farm. Skilled with her hands, she would purchase cotton wool and handcraft sweaters for her entire family.

Until she was around 94 years old, she lived alone, dedicating herself to her fields and gardening. She would read the newspaper cover to cover every morning to stay updated on social events. She kept herself well-informed about current affairs through her newspaper, so at one instance, when her great-grandson came to visit, she suspected it might be the “Hi, it’s me” scam, which is common in Japan. Until she was around 95 years old, she would walk to the hospital about 1 km away for medical treatment, and if she showed any signs of illness, she would seek medical attention immediately and prioritize her health.

At the age of 110, she resides with her daughters in her own home and does not heavily rely on welfare services. She consumes one full meal a day, preferring whole foods over chopped or pureed options. Her family notes that she maintains a strict regimen for herself but refrains from imposing her beliefs on others. Instead, she consistently embraces values that align with her era and demonstrates flexibility in her thinking. Moreover, she has always prioritized her health, maintaining a predominantly vegetable-based diet. Only occasionally does she eat snacks between meals, and until she reached about 100 years old, she prepared her own nutritious Japanese dishes, free from food additives.