He was born in Ōtawara, Tochigi and graduated from the Tokyo College of Commerce (now Hitotsubashi University) in 1942.

[1] Although he was ideologically opposed to communist China and favored Taiwan, he made efforts as Deputy Prime Minister to facilitate diplomacy between China and Japan in the wake of the 1989 Tiananmen Square protests and massacre, developing a relationship with the Chinese ambassador to Japan.

[2] He was hospitalized for gallstones in 1992, but rumors of a more serious illness spread shortly thereafter, and he resigned for health reasons in 1993.

After leading a Japanese delegation to North Korea in March 1995, he died from heart failure in September 1995.

[1] His eldest son, Yoshimi Watanabe, inherited his Diet seat and serves as the leader of Your Party.