Nezuko Kamado

She is a fictional character in Koyoharu Gotouge's manga series Demon Slayer: Kimetsu no Yaiba. Nezuko and her older brother Tanjiro Kamado are the sole survivors of an incident through which they lost their entire family due to the Demon King, Muzan Kibutsuji, with Nezuko being transformed into a demon, but unexpectedly still showing signs of human emotion and thought. After an encounter with Giyu Tomioka, a demon slayer, Tanjiro begins his quest to help his sister turn back into a human and avenge the death of his family (don't mind the pic)