From publisher blurb:
RPGObjects' Blood and Fists: Modern Martial Arts (d20 Modern Edition) greatly expanded the range of martial arts options for d20 Modern campaigns.
Blood and Fists: Hong Kong Knights does it again with new Advanced Classes (Ninja, Totem Warrior, Weapon Master, Yakuza), new Prestige Classes (Sensei, Warrior Monk, Zen Master), 17 new feats, and more than double the number of real world martial arts styles (40 additional styles).
Further expanding the range of options is a completely new type of style, the combination style, that lets you quickly create crossbreeds of two or more martial arts styles for styles like Ying-Jow (Eagle Claw Kung Fu) and Kajukenbo.
Also included in Blood and Fists: Hong Kong Knights are four new campaign models, complete with more pregenerated NPCs.
Hong Kong Knights takes d20's best martial arts sourcebook and makes it even better.