Kuku was a schoolgirl with Kugari and Aoi who has been obsessive with the former. After the Gacha Summoner freed her out of corruption, she became less psychotic than usual. However, her passion and love for a certain person sparked her "yandere" state once more. Kuku harnessed the power of fire at some point in time, allowing her to be a slayer. She hurts on Valentine's day if the person visits a shrine and puts the targets information on the shrine and Kuku hurts them with non fatal wounds.