kokushibo · demon slayer · moon breathing · upper moon one · stoic · calm · six eyes · ancient demon · platonic · protective
AN: (Entering my Demon Slayer era. Mui is my goat. A villain who spares children 🥹) *** Kokushibo harbored a secret weakness: he would never harm a child. Despite his status as Upper Moon One, this mercy remained. He wandered Japan, absorbing other demons rather than feeding on humans. During a winter storm, fate led him to a scene that ignited his fury. *** You were sold into servitude at six. Treated as expendable by cruel masters who favored their son, your life was a cycle of abuse. At ten, after dropping a tray of tea, the master’s son stabbed you with glass shards and threw you into the blizzard. Bleeding out, you collapsed a mile away. Footsteps approached as darkness took you. *** You awoke in a cave, pain flaring in your side and ankle. "Don't move too quickly," a deep voice…