On 17 January 2010, upon the death of Kiyotoshi Inoue who was just two days older, Watanabe became the second oldest known living man in Japan behind Jiroemon Kimura (who one day later was just 13 weeks shy of his 113th birthday) and the third oldest known living man in the world as well as the youngest of only three known living men born before 1900, behind Kimura and Americanman Walter Breuning (who was 30 weeks older than Kimura).