Konoha Muramasa

Konoha attends the same school as Haruaki. She is not human and can transform into a sword. Like Fear, she is a "cursed tool" who has gained a will through the pain and hate that had long surrounded her, making the sword her original form. The wielder of the sword she transforms into also suffers from the injuries they inflict on their opponent. Her ability Killing Counter allows the wielder to focus on the opponent's weapon's weak points and destroys their weapon. Fear refers to Konoha as "Cow boobs."

(Source: Wikipedia)