An honorable combatant, Ryu only enters tournaments to fight the strongest opponents and does not care for the reward the tournament offers. In Street Fighter 2 and its many updates, if Ryu wins, he just simply leaves the area because victory meant nothing to him.
He is best friends with Ken Masters and trained with him at the same dojo, so they have the same fighting techniques. Ryu is for the most part, a loner who wanders the Earth on his own. However, even though he is a loner, he has a kind heart and is willing to help those in need.
Because he is one of the strongest fighters, the evil but honorable Akuma, is interested in fighting him, but only if Ryu gives into the dark power within him. In Street Fighter 2: The Animated Movie, M. Bison also shows in an interest in Ryu in the hopes of making Ryu his ultimate terrorist warrior.