Tonbokiri

A yari (Japanese spear) crafted by Masazane Fujiwara, under the school of Muramasa. It is recognized as one of The Three Great Spears of Japan. The name stems from a legend that its blade was so sharp, a dragonfly stopped on its blade and was instantly sliced in half. He is very honest and sincere, and is primarily sent on missions in the Sengoku (Warring States) Era.

(Source: Katsugeki Toukenusa)