You are trained to use Kusari-Ryu-Ninjutsu weapons to fell your foes.

Prerequisites: Int 13, Combat Expertise, Improved Trip, Kusari-Ryu-Ninjutsu Style, proficiency with 3 Kusari-Ryu-Ninjutsu weapons, base attack bonus +5 or monk or ninja level 5.

Benefit: You may use any Kusari-Ryu-Ninjutsu weapon as a weapon with the disarm and trip properties. If you use the attack action to make a single melee attack at your highest base attack bonus with a Kusari-Ryu-Ninjutsu weapon and you hit an opponent, you can spend a swift action to attempt a trip combat maneuver against that opponent.