Lei-Fei is a Shaolin monk from China who entered the tournament under orders from a secret clan to kill Lau Chan. His clan stretches back to the days of ancient China when an emperor sought to supress certain martial arts that he considered too powerful and created the clan in secret to ensure that anyone caught using these styles in his kingdom would be killed. Though the emperor is long dead, the clan has not stopped with its mission. Because Lau Chan was a Chinese man who happens to know the secret "Tiger Swallow Fist" technique, Lei-Fei was asked to enter the tournament in order to hunt him down and kill him. However, Lei-Fei wishes to learn said technique from Lau...and then kill him when he's done.
Lei-Fei uses Shaolin-Ken, a fighting style that incorporates several different Kung Fu and Karate stances and offers several different methods of attacking the enemy, from fast combos to single hard strikes, and is considered one of the best characters in the game as a result.