"Ryu (リュウ Ryū, written as 隆 Ryū in the original Street Fighter) is a video game character created by Capcom, the main protagonist of the Street Fighter series.
Premiering in the first Street Fighter, Ryu appears as the lead character from the game along with his best friend Ken participating in the Street Fighter tournament. Further games from the series show Ryu to be highly focused on his training, aiming to become the strongest he can. However, his powers also attract several criminals who want to use him for their plans.
Ryu has been the lead character of the Street Fighter series since the first game and has appeared in crossovers involving the franchise. He is also featured in manga from the series, anime adaptations and the 1994 live-action film.
In the first Street Fighter game, Ryu has red hair and wears a tattered white karate gi with a white hachimaki (headband), red gloves and red shoes. Also, a constant trait in his design is the Fūrinkazan (風林火山) kanji motif (meaning Wind, Forest, Fire, Mountain), battle standard of the historical Japanese military leader Takeda Shingen, embroidered into his obi, simulating Karate Dan degrees. In Street Fighter II Ryu is shown to be older, with brown hair and a red hachimaki. He also fights barefooted this time. The Alpha series features a Ryu much like the one depicted in the original Street Fighter, with light red hair and a white hachimaki. In the Street Fighter III games, Ryu has black hair and facial stubble to show his growth in age. Street Fighter IV is chronologically set between II and III and so Ryu has a more mature look than he does in Street Fighter II but still not as aged looking as in Street Fighter III.
Because he was the only playable character in the original Street Fighter, Ryu's designer, Manabu Takemura, wanted to make him easy to identify with. In Street Fighter II, the character was selected for inclusion due to his presence in the first game, symbolizing the concept of a Japanese martial artist. As the series progressed, the design was made more muscular to coincide with the concept, while his white gi, considered his most defining characteristic by the development team, was meant to let viewers know he was "a karate master at first sight"."
Source: Wikipedia, "Ryu_(Street_Fighter)", available under the CC-BY-SA License.