When Ken was about 12 years old, his father, a rich hotel tycoon, thought that his son needed to learn about discipline, or his son would become a spoiled brat all of his life and try to leech onto the Masters' family fortune. In order to do so, the elder Masters sent Ken to Japan to train under his best friend, the mysterious karate master Gouken. At first, Ken was very hesitant to learn from Gouken, wanting to go back to the United States, but later began to respect his master. He even enjoyed the company of Gouken's adopted son, Ryu, since he had a foil to finally pull pranks on, although this got Ken into a lot of trouble. Ryu and Ken would later become best friends and each others principal rivals.
Ken is the complete opposite of his very friend. While Ryu is serious and detached, Ken is highly unorthodox and unpredictable. He can also be very short-tempered and arrogant, but his sheer determination always backs him up. He refuses to give up, no matter what the challenge may be. Like Ryu, he also believes in respect and discipline.