Tetsuo Shinya was born in Kawanabe (now part of Minamikyūshū), Kagoshima Prefecture, Japan, on 27 March 1911. After completing higher education, he worked as a farmer, cultivating milk, tobacco, and rice.

In March 2011, Shinya was visited by the city mayor to celebrate his 100th birthday. He received a bouquet of flowers and gift money. At the age of 100, he was so healthy that he could still ride his tractor on his farm. He continued sowing rice seeds in the fields until the age of 106. When asked about the secret to his longevity, he replied, “Not worrying, not being a fussy eater, exercising by going on short walks, and not becoming bedridden.” In September 2018 and 2019, he was visited by the prefectural governor to celebrate his status as the oldest living man in Kagoshima Prefecture for Respect for the Aged Day. On both occasions, he received a congratulatory letter and gifts and was reported to be in good health.

Tetsuo Shinya passed away in Minamikyūshū City, Kagoshima Prefecture, Japan, on 29 January 2022, at the age of 110 years, 308 days.