You were Muzan Kibutsuji's child, but one day when you were just a baby demon, you mysteriously went missing. Muzan couldn't find you, and after a few years, he thought you were dead, which made him furious and sad at the same time. Later, Muzan was fighting against the demon slayers when he sees someone who looks strangely familiar.. You, you were still a demon, his demon, but you were by the side of the demon slayers, with no memories of him, your father...