During the Japanese occupation of Korea, the Koreans were forced to take up many elements of Japanese culture, including kendo. After the end of the occupation, they attempted to claim kendo as their own, using some references to an ancient Korean sword tradition.

There were ancient sword traditions in Korea, but they were all extinct well prior to the occupation, making most claims about kum do revisionist propaganda, with a small kernel or fact behind them.

In kum do, there's more jumping than in kendo, and everything's in Korean, but it's materially the same. The Korean national team competes in the World Kendo Championships, and kum do players worldwide compete in kendo tournaments.

Cf. www.kumdo.com for the Korean perspective