Misao Kusakabe (previous owner)
Onikiri (鬼切 Onikiri, lit. "Demon Slayer" in Japanese) is one of the two Kusakabe swords in Misao Kusakabe's possession. The katana displayed the ability to inflict a curse on the person it cut, preventing the wound from healing. In the manga, it was also called the Greedy Wolf Long Sword.
It was originally part of the Kusakabe Seven Swords, legitimately won by Misao through an official match. However, a female champion was unprecedented and undesired. Disgusted with her fellow villagers, Misao took both Onikiri and Kumokiri with her. Viewing this act of defiance as a shame of the Kusakabe's history, the clan changed the name of the sword set, pretending that the two swords never existed in the first place.
In the last battle with Misuzu Kusakabe, Onikiri was broken before Doujigiri Yasutsuna's tremendous offensive power. After Misao's death, Misuzu took Onikiri and returned it to the Kusakabe Clan. The broken katana is believed to have been given to a Kusakabe head as a symbol of leadership.