While in Taiwan he got married to Mitsue who bore him five children.
He was born on March 5, 1907, and is the oldest brother to seven siblings.
To celebrate this announcement, an official certificate was presented to him at a nursing home in Niigata, where he now resides.
He then moved to Taiwan to work at Dai-Nippon Meiji Sugar. The oldest living woman, Kane Tanaka, is also Japanese. He returned to Japan after World War II and worked as a civil servant in his hometown until his retirement. "Having to live under that circumstance with four young children must have been tough", Yoko said.
The organisation recognised Watanabe as the oldest living male after the previous holder, Masazo Nonaka, of the northern Japanese island of Hokkaido, died on January 20, 2019, at the age of 113. She is 117 years old.
Following his retirement, in 1974 he and Tetsuo set up a one-hectare farm next to his family home.
Until about a decade ago, Watanabe used to do bonsai, the Japanese traditional art of raising small sculpted trees, and had his work exhibited. She lived to 122 years and 164 days before dying in August 1997.
At their farm, they grew all types of crops ranging from potatoes, tomatoes, strawberries and plums and this kept him going until he was 104 years old. "He's also caring. When I was working on my patchwork hobby, he was the one who praised my work the most", Yoka continued.
'I think having lived with a big family under one roof, mingling with his grandchildren and great-grandchildren helped keep a smile on his face as well'.