Masanori Toguchi debuted for Japan Pro Wrestling Alliance on August 30, 1968, against future NJPW referee Katsuhisa Shibata.

When JWA folded in 1972, Toguchi went to the United States, where he developed himself as a heel under his Korean real name, Kim Duk.

On June 10, 2018, at the age of 70, he won the WEW Heavyweight Championship defeating Daisaku Shimoda at a show for Pro Wrestling A-Team in Tokyo, Japan.

In September 2019, Kim Duk pulled out of Tokyo Championship Wrestling's (TCW) tour due to chest pains, which ended up being arrhythmia.

On May 31, 2022, Duk would wrestle his last match on at the Jumbo Tsuruta tribute show at Korakuen Hall, officially retiring after nearly fifty four years.

He returned on August 24, 2024 at the FMW-E Terry Funk Memorial & Atsushi Onita 50th Anniversary in Kawasaki, Japan, where he teamed with Yuichi Taniguchi defeating Chikara and Masahiko Takasugi.

In 1986, while wrestling in the U.S. for the WWF, Kim Duk made his acting debut as a henchman of Charles Dance's character, Sardo Numspa, in The Golden Child, which starred Eddie Murphy.

[5][6] Two years later, he portrayed a Georgian mobster named Andrei 'The Mongol Hippie' in the Arnold Schwarzenegger film, Red Heat.