Demon Slayer: What If Muzan Had to Raise a Child

[All demons x Tanjiro; Muzan and Kokushibo as friends; lighthearted daily life; happy ending. Tanjiro's whole family survives, Nezuko becomes a Hashira, Tanjiro becomes a demon, and Tanjiro reverses their roles to become Muzan's new dad (not really). The story has perspectives from both Tanjiro and Nezuko, so proceed with caution if that's not your thing.] After being reborn, Muzan's first move was to seek out Tanjiro Kamado. Instead, he found himself staring eye to eye with a child barely half his height in the snow. Muzan: What? I'm too early. Why is this kid only ten? After staring at each other for a long while, Muzan decided to take Tanjiro to the Infinity Castle. Muzan had originally planned to assimilate Tanjiro right away. But he thought, If he's going to be stuck as a ten-year-old for the rest of his life, that's just too cruel. I'll raise him a little longer, then turn him into a demon when he's grown up. Tanjiro had been thrown to the ground by Muzan and cracked his head against a railing. When he came to, he said to Muzan, "Father." Then he turned to Kokushibo, who had been standing by, and said, "Mother." Kokushibo: Oh.