Saw this bad boy on one of the History channels the other day. Its a silk, cloak-like garment worn by mounted samurai. When the samurai are riding, the silk billows out behind them, hopelessly entangling and deflecting arrows. When tested on the show, only a couple out of ten or so arrows, shot by an expert archer, even pierced the thing, and none did any harm to the rider!
Horo - 10gp This light silk cloak is worn when mounted, and is often embroidered with the sigil of the wearer. It conveys to its wearer an AC of 2 vs. missile attacks from the rear.