Kamikirimusi is a bonus character in Soul Calibur IV designed by guest artist Hirokazu Hisayuki. She is an oni, as her Japanese garb, horns, and the club she carries implies. In Japanese folklore, oni are demons that could be best approximated to ogres or trolls in Western folklore. Oni also traditionally wear tiger-striped loincloths, which Kamikirimusi seems to forgo in favor of more civilized attire.
Her primary weapon is an enormous, spiked club called a kanabō; the customary weapon of an oni. Like all of the bonus characters, Kamikirimusi's moveset is recycled from one of the main character's; she uses the same moveset as Nightmare. What lies within her soul is Despair.
During the Heian Period, Kamikirimusi, a female oni, destroyed the capital, causing her to be magically restrained by an onmyōdō practitioner. Although she found her punishment to be unreasonable, she decided to be good and submit to her restraints.
Some time later she realized she had control of her body again and that the restraints were gone. As her friends swarm out of the pit that had been their place of confinement, she thought about how her captor had said that they must stay longer. At first, Kamikirimusi was disappointed at this, though she decided to keep her promise and wait quietly in the pit for the appointed time came.
Six hundred years later, Japan was now in a period of civil war, and nearly all the supernatural power once feared in the capital was gone. Kamikirimusi's friends were nowhere to be found as they had all either been vanquished or faded away after their release. However, Kamikirimusi was finally free. As she took her first steps, she felt a great power that could make the world tremble, a power beyond that of any human.
She became drawn to it and began searching for this power.