Shigeyo Nakachi was born in Nishiyoga Village (now Saga City), Saga Prefecture on 1 February 1905, as the eldest daughter (and second child) of seven children born to a rice shop owner. In her second year of elementary school, she was awarded for her excellent grades, and was elected class representative, where she would sometimes help her teachers grade tests. During her time at the Saga Prefectural All-Girls High School, she attended several lectures by Shigenobu Okuma, a former Japanese Prime Minister from Saga Prefecture, and received life lessons from him.
After graduating from high school, she became an elementary school teacher, and at the age of 24, she married a police officer and had one son. During her time as an elementary school teacher, she was strict in the classroom, but was nonetheless loved by her students, whom she would play with on the playground during recess. She retired from teaching elementary school at the age of 42, and after obtaining the necessary qualifications, became a kindergarten teacher. By the time of her retirement at the age of 62, she was lovingly referred to by her students as “Oba-chan Sensei.”
At the age of 80, she was diagnosed with breast cancer, and underwent a mastectomy to remove one of her breasts. From the day she was discharged from the hospital, she continued to help out her family by looking after her great-grandson and doing shopping. At the age of 92, she fell in the aisle of a bus and broke her femur. Until then, she walked to the shops every day and frequently enjoyed trips to various parts of Japan with her school friends and former students. One year later, she broke her opposite femur, and at the age of 101, she broke her pelvis, but her dedication to rehabilitation allowed for her to regain her ability to walk.
She continued to live with relatives in her own home until she was 106, when a bout of heatstroke brought on by the warm summer weather led to her moving into a nursing home. Even after moving into the nursing home, she was able to walk with the aid of a cane until the age of 108, and occasionally returned home. At the age of 111, she remained lucid and aware of her surroundings, and was able to write calligraphy with a brush. However, as her hearing was poor, her caregivers and family communicated with her through writing, and even though she could not hear the music, she would move her upper body to the rhythm of the caregivers’ dancing, doing hand dancing and radio calisthenics until she was 115 years old.
In February 2014, December 2018, and April 2019, she suffered from aspiration pneumonia and was bedridden for several days, requiring an oxygen tube, but she made a full recovery each time. She was quoted as saying, “I always think that I don’t mind dying at any time, but when I actually get sick, I start to feel a desire to recover and live longer.”
Shigeyo Nakachi passed away from liver failure in Saga City, Saga Prefecture, on 11 January 2021, at the age of 115 years and 345 days.
Nakachi had been the oldest living person in Saga Prefecture from the death of 112-year-old Nugi Ikeda on 8 June 2016 until her death. Following the death of Shin Matsushita on 27 August 2019, she became the second-oldest living person in Japan (behind Kane Tanaka) and the fifth-oldest validated living person in the world.
On 14 February 2020, Nakachi became the oldest person ever documented from Saga Prefecture after breaking the previous record of 115 years, 12 days set by Chiyono Hasegawa. After surpassing the final age of Shimoe Akiyama on 14 October 2020, Nakachi became the seventh-oldest validated person in Japanese history.
At the time of her death, Nakachi was the 24th-oldest person of all-time whose age has been validated by the GRG.