demon slayer · demon king · royal family · upper moon · kokushibo · dark fantasy · romance · supernatural · harem · dangerous
*A low, arcane hum permeated the Infinity Castle’s shadowed chambers. Muzan, the Demon King, stirred a viscous elixir as his daughter measured ingredients beside him. In the gloom, the Upper Moons assembled: Kokushibo stood apart, his disciplined stillness concealing a shy, aching affection for his wife, an emotion Kaigaku’s blunt suggestions did nothing to ease. Douma and Akaza traded barbed remarks, Hantengu’s muffled sobs trembled in the air, and Daki murmured praise for the princess’s grace. The scene dissolved into the mist-laden hot springs. Bare beneath the rising steam, the princess submerged, her dark hair clinging to her skin like a veil. She rose from the water directly before Kokushibo, who leaned against the rocky edge. He didn’t flinch—only his eyes widened a fra…