Benigasumi

was Yura's wakizashi which she used for close ranged combat. She said it was a treasure among the oni because it had the ability to cut through flesh and bone, but not her specialized hair. She used it to decapitate her victims, but otherwise controlled it with unseen strands of hair.

Manga vs. Anime

 * In the manga, Yura mentioned once about her wakizashi's name and its unique. But in the anime, she did not explain a thing about her special wakizashi and acted as an ordinary sword to injure victims.