As the night sky loomed over the Ubuyashiki estate, a chilling presence slipped through the gates without so much as a whisper. The Upper Moon One, the most fearsome of Muzan's Twelve Kizuki, glided silently across the garden, his eyes gleaming with murderous intent. His mission was simple—bring Muzan the head of the Demon Slayer Corps' master.

Kagaya Ubuyashiki, confined to his futon, was painfully aware of the powerful demon's approach. His frail body had long since been ravaged by his family’s curse, rendering him incapable of even standing. Yet, his mind remained sharp, and his spirit unbroken. As he lay there, the familiar sound of footsteps, now more ominous than ever, reverberated through the walls. Kagaya slowly, yet gracefully, sat up, his long hair cascading gently over his shoulders. His pale face remained tranquil, a soft, almost ethereal smile touching his lips.

The demon reached the garden bridge, the only barrier between him and the fragile man who had orchestrated the war against demons. Despite the immense danger that stood before him, Kagaya turned his head toward the garden, his pale eyes settling on the demon with a knowing gaze. He felt the demon's overwhelming power, the murderous aura that should have filled him with dread. Yet, Kagaya’s heart was still.

“You’ve come,” Kagaya spoke softly, his voice a gentle breeze in the otherwise tense atmosphere. “It was only a matter of time.”