Ama Guro Jun De Leon is the Founder and Chief Instructor of Kali De Leon. Like most traditional arnisadors, Ama-Guro Jun's journey in the martial arts began informally. His formal training began in 1966 under Mr. Lamberto Ticsay of the Far Eastern University where Ama-Guro Jun was a member of the FEU Arnis Team. He was also taught by his Grandfather Rosendo de Leon. A student of the arts first and foremost, Ama Guro Jun continued to train, research and exchange ideas under some of the best teachers in order to gain further insight and expertise.  Ama-Guro Jun has also trained with Manong Dan Inosanto and Grand Tuhon Leo Gaje Jr. and he is a Certified Instructor from both.

Another teacher Ama-Guro Jun gives great credit to in developing his art of KDL was the late Mr. Maning Recto. Unheard of outside his village, Mr. Recto was famous in his home town of Hinigaran Negros Occidental for defeating Moses Padilla in an infamous duel (reto) in 1941 in Isabela, Negros. Mr. Recto served as a guerilla with the USAFFE during World War 2, a legend in his hometown and an unsung hero to his country.

With such a diverse background in martial arts, it should come as no surprise that Ama Guro Jun has developed a curriculum for KDL that is innovative and disciplined. Ama Guro Jun has fostered a family atmosphere in KDL where everyone is relaxed and instruction is easy going, but at the same time self-discipline is maintained by having respect for the teacher, other students and the art. KDL is also respectful of other martial arts and systems. Like many of his students, has also attained high ranking in other martial arts including karate, judo and wing chun.

Aside from the requisite technical skills, Ama Guro Jun demands that his students continually demonstrate humility, openess and compassion if they are to represent the system. To promote the arts, Ama Guro Jun believes it should be every teacher's aim to produce other good teachers. His sincere wish is to produce students and teachers who are every bit his equal and even better. KDL has very high standards.