Кен Мастерс

Ryu's best friend and the only son of the extremely rich Masters family. He lives in San Francisco with his parents in a very large mansion (it takes 20 minutes to drive from the front yard to the main house). He too spends a lot of time training as well, but not as much as Ryu. Ken also rides a motorcycle. His mother is Japanese. Ken also learns to use the power of Hadou later on while being held captive by Shadowlaw. Only Ryu knows the Hadoken, while both he and Ken know the Shoryuken. Ken later upgrades the Shoryuken to the Hadou Shoryuken, and then shortens it to the Hadou Shoryu.

Interestingly, in the English dub Ken still called the move Shoryuken while Ryu called it by its English translation; Rising Dragon Punch. (Source: Wikipedia)