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.

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.