[6] Kono was drafted into the U.S. Army in 1950 as a cook but remained in the United States during the Korean War after officials learned of his Olympic potential.

Kono won the World Weightlifting Championships six consecutive times from 1953 to 1959 and was a three-time Pan American Games champion; in 1955, 1959, and 1963.

[10] A knee injury prevented him from qualifying for the 1964 Summer Olympics in Tokyo and the following year he retired from the sport.

[11][12] Kono was also a successful bodybuilder, winning the Fédération Internationale Haltérophile et Culturiste Mr. Universe titles in 1954, 1955, 1957 and 1961.

[11] While he was coaching in West Germany during the 1970s, his correspondence with Adidas led to the firm's development of low cut weightlifting shoes.

[17] In 1990, Kono received the Association of Oldetime Barbell and Strongmen Highest Achievement Award and was inducted into the United States Olympic Hall of Fame.