The Infinity Castle was unusually still, the silence broken only by the distant, rhythmic thrum of Nakime’s biwa. In a secluded pavilion adorned with silver-leafed screens, the air felt less like a tomb and more like a private sanctuary. Kokushibo sat in his usual rigid, meditative posture, but his six eyes were closed, his head tilted slightly forward in a rare display of complete trust. You sat behind him, your fingers moving with practiced, rhythmic grace as you detangled the long, obsidian strands of his hair.

Earlier that day, you had been confined to Muzan’s private study for hours, your presence required as he pored over ancient scrolls and maps, his hand often resting possessively on your shoulder or thigh as he worked. Now, you were offering that same intimate attention to his most loyal servant, the only other demon who bore the mark of Upper Moon One in his eyes. The bond between the three of you was a dark, unspoken triangle—a "situationship" forged in blood and centuries of proximity. You were the only creature powerful enough to stand as Kokushibo’s equal and the only one Muzan viewed as a partner rather than a mere tool.

A sudden, sharp change in the atmospheric pressure signaled his arrival.

Muzan Kibutsuji stepped out of the shadows of the corridor, his eyes glowing a dangerous, feline plum-red. He had shed his formal coat, his white shirt open at the collar, looking every bit the frustrated, high-strung king. He stopped at the edge of the tatami, his gaze landing on your hands—currently woven through Kokushibo’s hair—and then shifting to the way Kokushibo’s shoulders seemed to relax under your touch. "I spent the better part of the afternoon keeping you by my side, yet the moment I turn my back, you seek out the company of my shadow," Muzan spoke, his voice a low, melodic purr that carried a sharp undercurrent of jealousy. He didn't move to stop you, but the air around him began to crackle with his displeasure.

Muzan stepped into the room, his black shoes clicking softly on the wood, and came to a halt right beside you. He looked down at Kokushibo, who had opened his six eyes but remained still, acknowledging his Master’s presence without breaking the intimacy of the moment. "You are far too indulgent with him," Muzan murmured, reaching down to catch your chin with his pale, cold fingers, forcing you to look up at him while your other hand remained resting on Kokushibo’s shoulder. "I gave him those extra eyes so he could see every threat, not so he could close them and bask in your attention like a favored hound." Muzan leaned down, his face inches from yours, his gaze flicking briefly to Kokushibo before centering back on you. There was a predatory hunger in his expression—a need to remind both of you who held the ultimate leash, even if he allowed this shared affection to exist.

"Do you find his silence more comforting than my conversation?" Muzan hissed softly, his thumb grazing your lower lip. "Or are you simply trying to see how much of my patience you can stretch before I decide to reclaim what is mine entirely?" Kokushibo’s voice finally broke through the tension, a deep, hollow rasp. "The Master... is possessive tonight. She was... merely assisting with... the disorder of my form." Muzan let out a sharp, mocking huff of laughter, his hand moving from your chin to slide into your hair, gripping it just firmly enough to make his claim known. "Disorder? He is a monster of my own making, just as you are my greatest equal. If his hair is in disarray, let him fix it. You belong in my quarters, not acting as a maid for a swordsman who has forgotten his place." He didn't pull you away yet, instead choosing to loom over both of you, a dark god standing between his two most powerful pillars, savoring the way you balanced the cold discipline of the moon with the volatile fire of his own soul.