The Wude (武德 wǔdé) are four aspects that any Martial Artist of true virtue should know. In order for Ryo Hazuki to meet with Xiuying Hong he must learn the four wude. It is said that those without the wude often stray from the right path and are hated by others, sometimes even killed. Xiuying comments when she first meets Ryo that he only possesses GON and DAN.
GON - Everyday, without neglect, to keep training
DAN - Be brave and stay calm to make the right decision
JIE - Judge yourself without conceit and do not show moves thoughtlessly
YI - To act without hesitation, to do what is right