Nonaka, who was the oldest living Japanese man since 112-year-old Masamitsu Yoshida's death on 29 October 2016, became the world's oldest living man after the death of 113-year-old Spaniard Francisco Núñez Olivera on 30 January 2018 (Núñez Olivera died on 29 January 2018 CET), and credited his long life to eating sweets and bathing in hot springs. Nonaka was also the oldest living person in Hokkaido since Teru Hatakeyama (who was just five days older) died on 3 April 2016.