<b>Pre-Street Fighter</b>

When Ken was about 12 years old, his father, a rich hotel tycoon, thought that his son needed to learn about discipline, lest his son 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 other's principal rivals.

When Ryu was 18, Gouken decided that both of his pupils had grown up to be fine fighters and decided that their training was over and could now leave the dojo. Ryu decided to travel the world in order to continue his training, whereas Ken was finally happy to be going back home to the United States after his years of straining his back for master Gouken and finally learning the meaning of humility. After coming home, Ken competed in many different Martial Arts tournaments held in the United States, winning most of them.


<b>Street Fighter Alpha</b>

Ken did not participate in the first Street Fighter tournament; instead, he fought in (and won) the premiere U.S. Martial Arts tournament that had been previously won by Charlie, as well as meeting a very attractive girl named Eliza, who became his girlfriend.

After winning the U.S. martial arts tournament, Ken returned to his training ground to tell his master Gouken the good news, he witnessed his master's death at the hands of Akuma, and tried to fight him, but was defeated.

He began wandering the world in search of Akuma, and his friend and fellow student Ryu. He wanted to tell Ryu what happened to their master and also hoped to win a match against him. Along the way, he fought and defeated Dan, who had unwisely taunted him with copying Saikyo-style moves. He eventually finds Ryu in seclusion. Ryu is dejected upon seeing his long-time friend, but Ken makes him go try out a spar anyway. Over the next few days, Ken realizes how stressed out his best friend is since his fight with Sagat. Ryu explains to Ken that deep within him there is a burning rage. A power trying to overcome him. Giving Ryu his red headband, Ken tells him to stay focused, which greatly cheers Ryu up. Ken returns home and begins training harder. Knowing even with his recent feelings, that Ryu is always stronger than he looks.

Ken begins to wonder about his own life. Ryu seemed to be on the right track again, but what of him? Along the way to prove himself again, he encounters Karin who tells him she has followed his career and is trying to best her rival Sakura's to prove she is superior. Ken advises her it's good to have a rival, but not for supremacy, but to keep on training harder and focusing. With this, Ken finds himself again and is focused once more. Going off to meet up with Sakura, they too have a friendly match and Ken finally realizes that Ryu has the right idea all along. Both he and Sakura begin to travel to find Ryu, but find out that he's being brainwashed by the dictator Vega. Ken and Sakura both take Vega on together to distract him as Sagat (who had come along to also find Ryu struggling against Vega) took Ryu under control. Ryu eventually came to and slammed Vega away with the help of Ken, then talked to each of his friends — he told Ken to wait for his rematch, noting he still had much to learn. Ken himself promised to train harder.


<b>Street Fighter II</b>

Ken received an invitation to the second Street Fighter tournament, but since his last U.S. Martial Arts tournament, he has let himself spend too much time with his girlfriend and not training. Only when Ryu challenges him rekindles Ken's fighting spirit and causes him to enter the tournament. Ken fought Ryu in the second World Warrior tournament. Because Ken had stated that he would only marry Eliza after winning a decisive fight against Ryu (after Street Fighter II, Ken and Eliza are married), it is widely speculated that he was victorious against his rival.


<b>Street Fighter III</b>

Ken then entered the third Street Fighter tournament. By this time, a Brazilian teenager named Sean had been pestering him to become his student, and Ken reluctantly accepted, beginning to train him. He fought Sean and won against him in the tournament; having defeated Ryu again, Ken commemorates his victory by beginning to train his son Mel in rudimentary fighting techniques. He also told Sean to go find Ryu and challenge him, giving him some free time with Eliza.

Though bored, Ken hears about a mysterious organization and goes to investigate, and may have confronted Urien. He does win his third straight U.S. Martial Arts tournament victory, which is a new record, and offers the trophy to Sean, although his student says he wishes to earn it for himself. He also learned that Ryu had sought him out and traveled all the way to New York from Oakland for their long-awaited rematch. Tossing some friendly jabs at each other, both have a good fight that Ryu wins. Since then, Ken has continued to train Sean and Mel, handle his family and business, and keep up with his old friend Ryu.