Shigechiyo Izumi
Shigechiyo Izumi (? - 21 February 1986) was a Japanese Centenarian who was recognised as the oldest living person in the world after the death of Niwa Kawamoto on 16 November 1976. Izumi's claimed birthdate of 29 June 1865 was accepted by Guinness World Records, which recognised him as the oldest verified man ever, but in the 2012 edition of the Guinness World Records book, he was not mentioned and was replaced with Christian Mortensen.
After a brief hospitalization, he died of pneumonia at 9:15PM (Japanese UTC) on 21 February 1986 at the age 120, although some claim his birth certificate belonged to a deceased brother. And his family might have used Shigechiyo as a necronym.
Obituaries were found of a centenarian with the exact same name but born in 1880 instead of 1865.
The oldest undisputed case of male longevity is Jiroemon Kimura, also from Japan, who died on June 12 2013 aged 116 years and 54 days.