Ken Masters is the best friend and chief rival of Ryu, the Street Fighter champion. He constantly seeks to prove to his friend that he is the better fighter of the two. His flashy flamboyant style is of stark contrast to Ryu's calm and methodical approach to all things, as Ken seems to be ruled by his emotions...

Ken's father, hoping to instill some discipline in Ken, sent Ken to train in the martial arts at an early age. He trained in the art of Goutetsu Shotokan Karate, along with his friend Ryu under the mysterious fighting monk named Gouken.

He and Ryu went their separate ways after 10 years of training under Gouken. They met up again in the very first Street Fighter tournament, and had to face each other before facing the champion. Ryu narrowly defeated Ken and faced Sagat, and won the coveted Street Fighter championship.

After the first Street Fighter tournament, Ryu and Ken returned to Gouken's dojo to train. But they found their master locked in combat with a demonic foe high up in the mountains. They watched the apparent slaughter of their master, unable to overpower the skilled demon-man, who simply threw the two young boys aside. Saddened by the loss of their master, the two parted, each deciding to go his own way. Ken swore vengeance over Akuma for the death of his master, and proceeded to search the globe for Akuma. Ken retunred home and won the All-American Martial arts tournament Championship from then-champion Allen Snider, who, since then, has longed for a rematch against Ken, who beat him easily, then proceeded to taunt him, humiliating Allen further...

Ken later received and invitation to the Alpha Tournament and entered in hopes of finding Akuma, and also meeting up with Ryu for a rematch to prove he was the better of the two, and that Ryu had merely gotten lucky the last time. What Ken found was the mad dictator M. Bison, whom quickly took control of his mind, and used him as a pawn against Ryu. Ryu was able to get through to Ken, and the two combined forces to defeat the powerful dictator. After the tournament, Ken returned to America, where he met and fell in love with a young woman named Eliza. He revealed to her that he fought with such ferocity simply because he was searching for someone who he must make pay for what he had done...

In the second Alpha tournament, Ken finally met up with a distracted Ryu for a rematch. Ryu, bothered by his encounters with both an angry Sagat and the powerful Akuma, subconsciously allowed Ken to win the match. Ken sensed that Ryu was not at the top of his game, and told him to concentrate more and forget about Sagat. He gave Ryu his hair ribbon as a reminder of this day, when Ken actually defeated him. But Ken took no pride in this victory, as he knew Ryu was very troubled at the time...

Ken spent the next couple of years spending time with his girlfriend Eliza and helping his father in their family's financial pursuits. It was only a challenge from his long-time friend and rival, Ryu, that piques Ken's competitive spirit and goads him into entering the second Street Fighter tournament, again attempting to seek out Ryu and the villainous murderer of Gouken. However, this time, the host, M. Bison was taking no prisoners. He carefully calculated every move, and ensnared all the combatants in a deadly game of cat and mouse. He used his psycho powers to once again control Ken in a fight against Ryu. He was once again able to snap Ken out of Bison's control, but Ken was previously injured from his fight against Ryu's mortal enemy, Sagat, whom Bison sicced on Ken as a means to capture him. Ken could only watch as Ryu and Bison battled.

After the second Street Fighter tournament, Ken returned home, and married his long-time love Eliza...

By the time the third Street Fighter tournament was announced, Ken was already a father. Ken gave up Street Fighting because of his familial duties, but Eliza and he reached an understanding whenever Ryu was involved. Eliza only allowed Ken to participate if Ryu himself was one of the competitors. However, the bonds of friendship that he and Ryu had were strained by his choice to raise a family, as he had not heard from his friend in nearly three years. Ken chose to enter the third Street Fighter tournament to attempt to rekindle the friendship between the two lifelong warriors, and to again attempt to show Ryu that he was the better fighter of the two.

This time however, Ken brought along his understudy, Sean, who begged and pleaded with Ken to train him in the martial arts. Ken reluctantly took him around wherever he fought so he could observe, but he refused to train him. Ken ended up once again ensnared in a deadly game by the organization controlled by the malevolent being called Gill, and was locked in mystical combat with Gill's brother Urien as a helpless Sean watched. After it was over and he had defeated Urien, he simply told Sean that if he wanted to be the best, he should seek out Ryu, and attempt to defeat him. Ken then returned home and decided it was time to teach his son the ways of the martial arts.