Ken grew up in a world of violence. He mastered the martial arts at a very early age and went on a global tour to challenge the greatest Street Fighters of the world. He was victorious. Upon returning to his home country he enroll- ed at Bargham University and began his life study in the field of Cybotics. While at Bargham, he was befriended by a gifted classmate named Troy. After many years, they perfected a revolutionary discovery they named Cyboplasm.
This substance, when properly administered, could make a man several times stronger than normal. This came at a good time, for mankind had just perfected travel to the "frontier" of other worlds. Ken had no interest in traveling to the new frontier, but he was glad their invention could be helpful.
One day he came to their lab and found it nearly destroyed. His partner Troy was killed, and their formula was stolen. The killer escaped to the new worlds. Ken knew he must avenge his fallen friend. He now has a very keen interest in the frontier...
--From the NES Street Fighter 2010 instruction manual.