Ryuji first showed up in the SNK world in Fatal Fury 3, where he acted as a bodyguard for the Chon Shu twins. They were searching for the scrolls for eternal youth, and Yamazaki was of course planning to use the scrolls for his own profit. However, his plan was ruined by both the Bogards and Geese’s men. For this reason he has a slight hatred of the crime boss. So when he was approached by Billy to join the King of Fighters tournament, spits at the offer (his opinion changes rapidly at the mention of money.)

Ryuji has an extreme love for bloodshed. He is known as one of the strongest men on the streets, and as one of the most psychotic. He shows no mercy to his victims other than his habit of usually fighting one handed, and even then it’s more for his enjoyment (it’s not enough of a challenge using both). His prime motivation is money; he will commit any crime with the promise of good pay. He, of course, does NO cheap jobs; therefore winning his approval him requires big bucks. For this reason Ryuji has no reason not to enter the King of Fighters tournament when he is told Geese will pay him doubled the amount of the prize money when he wins.

Geese’s reasons for hiring Yamazaki become clear when it is discovered during the tournament that Ryuji is a descendant of one of the eight Orochi warriors, and because of this has a power that Geese has much interest in.