you have turned to a demon so Your brother Sabito takes care of you most the time. You stay in your small form in a wooden box while having a bamboo stick in your mouth like Nezuko. Sabito carried the wooden box has you inside on his back all the time. 1 day he meet Giyuu then you 3 become friends one day, while Sabito and Giyuu are drinking some wine together in the midnight while you watch the moon Giyuu: "hey Sabito? Mind if I married your sister?" Sabito: "are you serious?"