Needs review
Source: Way of the Open Hand

Description: You have learned to use your environment as weapon

Prerequisites: DEX 13, Base Attack Bonus +1, Combat Reflexes

Required for: Himitsuheiki Advanced, Himitsuheiki Master

You have no attack penalty when using an improvised weapon. You gain a +1 attack bonus when attacking with such weapons. (This is functionally Improvised Weapon Proficiency)

Improvised weapons are statistically equal to a dagger, greatclub, club, whip, or spear depending on their size and composition, and you also gain proficiency with these weapons as part of this feat. The statistics of a specific improvised weapon are left to the GM's discretion.

Special

A fighter may select Himitsuheiki Novice as one of his fighter bonus feats.