Koyuki Kosaka

Koyuki Kosaka (21 January 1903 – 1 October 2013) was a Japanese supercentenarian whose age is validated by the Gerontology Research Group (GRG). She was the oldest known person in Ishikawa Prefecture at the time of her death.

Biography
Koyuki Kosaka was born on 21 January 1903 in Japan. On 17 September 2012, aged 109, she became the oldest living person in Ishikawa Prefecture following the death of 111-year-old Soto Yamamoto. She would hold that title until she passed away on 1 October 2013 at the age of 110 years, 253 days.

Kosaka was originally validated as having died on 2 October 2013, but subsequent research indicated that she actually died on 1 October 2013. She was succeeded as the oldest person in Ishikawa prefecture by then-110-year-old Iso Nakamura (1903-2017).