Ryuji Yamazaki is one of the villains from Fatal Fury.
Yamazaki was an orphan who lived a miserable life in the streets of Okinawa. One day, a Yakuza boss saw him and offered him to join his mafia. Yamazaki, with nothing better to do in his life, accepted the offer. Yamazaki started to idolize his boss, aspiring to one day become like him. He eventually climbed the mafia, becoming right-hand of his master. One day, his mafia was ambushed by a rival gang, who killed his boss. Yamazaki was greatly shocked, going nuts and slashing everyone in the place with his pocket knife which his boss had given to him as a memento. He chased down every single member of the rival gang, killing them all in cold blood while laughing maniacally. Yamazaki then becomes the boss of the mafia, working with drugs and weapons dealing. Some time later he moves to China, where he starts working to the Chinese mafia. It is then that he becomes pursued by Chinese law officer Hon Fu, who had little success in capturing Yamazaki. Yamazaki is hired by the twins Jin Chonshu and Jin Chonrei to serve as their bodyguard and search the city of Southtown for the Sacred Scrolls. On the lose in the city, Yamazaki meets with many others who are also after the scrolls, eventually finding their location and informing the Jins. Hon Fu, who pursued Yamazaki this entire time, caught up to him and fought him, but Yamazaki badly beaten him. It's then that Terry Bogard arrives at the place with Cheng Sinzan. While Cheng takes Hon Fu to a hospital, Terry faces Yamazaki and defeats him. Yamazaki tells Terry the location of the scrolls and the Jins, fainting shortly after. The Jins were defeated, but Yamazaki was nowhere to be found. He continued to search for the scrolls after they were stolen by Geese Howard, facing Hon Fu once again. Hon Fu seemingly defeated Yamazaki, but he suddenly went crazy and slashed Hon Fu viciously, leaving him alive and escaping.
Yamazaki has two different personalities. In one he is calm and calculated, which is the personality he remains most of the time. His other, hidden personality is that of a sadistic and insane psycho, who loves to slash everyone and everything.