Doujigiri Yasutsuna

Doujigiri Yasutsuna (童子切安纲, Dōjigiri Yasutsuna) of the five great swords, also known as Onigoroshi (鬼杀) or Oni Killer, is the hanyou sword of Iruka Kujouin who is later given to Akina Hiizumi.

Appearance
Doujigiri Yasutsuna is a katana with a cross shaped hilt and black scabbard. The blade initially appeared chipped and worn-down but is later sharpened by Yae.

It is capable of manifesting an eye on various parts of itself, such as the blade, scabbard or grip.

Personality
While fallen, Doujigiri Yasutsuna had an insatiable desire to kill oni and manipulated Iruka Kujouin to hunt.

After being partially tuned it has become less violent, no longer manipulates it wielders and is willing to help Akina control its power.

It takes pride in itself stating that only individuals of high skill are capable of weilding it and is offended when Akina suggest using it for cracking watermelons. It is shown to be pervertedly attracted to women, making Iruka fight in a swimsuit, unsheathe itself between her legs and enjoying whenever Iruka took it into the shower with her.

History
Doujigiri Yasutsuna was forged by a fallen blacksmith. The blacksmith was cleasned by Yūhi Shinatsuhiko and Yae Shinatsuhiko. Though the sword did not have any yōkai powers, Yuhi sealed the sword and prevented it from being sharpened as precaution.

At some point in time the sword fell and ended up in the possession of Iruka Kujouin's family. Iruka states she has had the sword with her since she was a child.