As the progenitor of all demons—the absolute sovereign of their kind, a being that stood infinitely close to perfection—Muzan Kibutsuji held dominion over every demon's life and death.
The strength of a demon was, in most cases, directly tied to the amount of his blood they had received. The more he granted, the stronger they became. In the beginning, demons could grow by devouring human flesh, but once they reached a certain threshold, their growth would stagnate. Beyond that point, only more of Muzan's blood could push them further.
And so, a paradox took root in the hearts of all demons: though they feared him utterly, they also craved him with equal intensity. His blood, his flesh—both were objects of boundless desire. Deep within nearly every demon lay the same forbidden thought: to consume him.
Muzan, a being capable of perceiving the minds of others, had always been keenly aware of this truth. He had never let his guard down. The possibility of betrayal was something he had anticipated from the very beginning.
Even now, he had not forgotten Tamayo, the demon who had once escaped his control. His pursuit of her had never ceased.
And yet, her escape—though infuriating—had at least been understandable. It had occurred during his weakest moment, when he had been gravely wounded.
But this…
This was something else entirely.
A demon had slipped free from his control in complete silence, at the height of his power.
That was something he could not accept.
"Which demon… was it?"
For as long as he could remember, Muzan had maintained a degree of surveillance over nearly all demons. The stronger the demon, the tighter his grip. And yet, now that he searched through his awareness, every likely candidate remained firmly within his control.
The Twelve Kizuki—those most capable of breaking free—were still bound to him. Those with the potential to rise to their ranks were also accounted for. Even the moderately powerful ones remained under his dominion.
Which meant…
The one who had escaped was likely a lesser demon, created on a whim.
Such demons were usually weak, driven by nothing more than an insatiable hunger for human flesh, their minds dull and undeveloped. Most of them were swiftly hunted down and slain by the Demon Slayer Corps. They were beneath his notice—insignificant, disposable.
And yet, one such insignificant being had done the impossible.
"How did such a demon slip from my control without a trace?"
Muzan narrowed his plum-red eyes, a rare flicker of contemplation passing through them.
For reasons he could not fully grasp, his thoughts drifted back to an incident several months prior—something unusual that had occurred with Akaza, the Upper Rank Three of the Twelve Kizuki.
Akaza had always been under close watch, his potential too great to ignore. Normally, he was simple in nature, singularly focused on becoming stronger.
But on that day… his emotions had surged violently, almost breaking through Muzan's control. Had Muzan not intervened in time—had he not suppressed the memories buried deep within Akaza's mind—the outcome might have been very different.
At the thought, Muzan's eyes darkened further.
...
Meanwhile, far from that suffocating presence, the mountains stretched endlessly in shades of vibrant green. The forests were lush, alive with the breath of summer, mirroring the lightness in Soma's heart.
For so long, he had existed as a creature of darkness, dwelling in shadows, his very being recoiling from the sun with a fear that seeped into his bones. Something as simple as standing beneath sunlight—once an ordinary part of his human life—had become an unattainable dream after his transformation.
And now…
Though he remained a demon, he could stand beneath the sun.
The sensation was not entirely pleasant—his body, still that of a creature born of darkness, instinctively resisted the light—but the joy that welled within him far outweighed that discomfort.
If Muzan were to see him now, standing openly beneath the sun… he would likely want nothing more than to devour him whole.
The thought drew a faint smile to his lips.
Lost in his musings, Soma suddenly noticed movement along the mountain path ahead. A small group of men, clad in the uniform of the Demon Slayer Corps, were approaching.
At the sight of them, instinct stirred—an old habit urging him to retreat, to avoid them.
He took a step back.
Then paused.
His gaze dropped to the ground, where his shadow lay clearly cast beneath the sunlight.
For a moment, he simply stared at it.
Then, quietly… he laughed.
The laughter burst from him, full and unrestrained, carrying a sense of liberation he had never known before.
To stand beneath the sun—what demon slayer could possibly look at him and think he was a demon?
Could demons walk in daylight?
In this world, was there even a single demon who could endure the sun's embrace?
Not the Twelve Kizuki. Not even their progenitor—Muzan Kibutsuji himself—could withstand it.
And yet here he was.
Soma laughed as he watched the group of Demon Slayer swordsmen approach. Behind him, Kanao tightened her grip around his arm, her small hands clutching instinctively.
He could feel it—the way her soft body tensed all at once, like a cat poised on the edge of a fight, ready to spring at any moment.
"It's alright," he said gently, turning his head slightly to reassure her.
"Uncle… I'll help you kill them," she whispered, her voice low and steady. Her pink-violet eyes had already fixed on the approaching swordsmen, instinctively marking their vital points—the heart, the throat—calculating how to end them in a single strike.
Soma couldn't help but laugh under his breath, a mixture of amusement and helplessness. Reaching up, he lightly tapped her on the head.
"A young lady shouldn't always be thinking about killing. You need to be more gentle, or no boys will like you in the future."
Kanao blinked, confusion flickering in her eyes. She glanced again at the approaching swordsmen, unable to quite understand.
These people had always been hostile toward her uncle. Every time, they came with blades drawn, intent on killing him. If she didn't strike first, wouldn't they simply attack him instead?
Waiting for them to make the first move… that didn't make sense.
She didn't fully understand—but Uncle's words were always right.
Even so, she remained on guard. If they made even the slightest move, she would step forward without hesitation, blade in hand.
She would never again allow him to fight alone.
Even if she could not stand in front of him, she would stand beside him.
Soon, the group of swordsmen drew close. One of them stepped forward first, offering a slight bow.
"Excuse me, sir," he said politely. "May we trouble you for a moment?"
Soma came to a stop, his gaze resting quietly on the man. His hand tightened briefly at his side—an old reflex—but just as quickly, it relaxed again. A faint look of curiosity appeared on his face.
"What is it?" he asked.
"We've lost contact with one of our companions," the swordsman explained, a trace of concern in his voice. "He mentioned coming to these mountains to pay respects to the dead, but we haven't heard from him since. We were wondering if you might have seen him. He's not very tall—about chest height compared to you—and he wears the same uniform as us. Thick eyebrows, and there's a mole above his lip…"
As he spoke, the swordsman watched Soma with quiet hope.
"I'm sorry," Soma replied, shaking his head. "I haven't seen him. If I do, I'll let you know."
"…I see."
The swordsman sighed softly before bowing again. "Thank you for your time. Sorry to trouble you."
"It's no trouble," Soma said with a gentle smile.
Then, after a brief pause, he tilted his head slightly, his expression still warm.
"By the way… do you notice anything different about me?"
"…Huh?"
The swordsman looked up, puzzled.
"I mean," Soma continued with an easy smile, "is there anything about me that seems… unusual?"
The swordsman found Soma's question rather strange, but having just asked him for help, it would have been impolite to ignore it. So he smiled and answered sincerely:
"Well… you're quite tall, sir—taller than most people. You look strong, too. There are calluses on your hands, so I'd guess you've trained with a sword. And… you're quite handsome as well."
Soma shook his head lightly, his gaze still resting on the man with quiet patience.
"That's not what I meant."
The swordsman blinked, confusion deepening.
"Then… what do you mean?"
Soma's smile remained gentle—almost playful.
"Have you ever thought… that I might be a demon?"
For a fleeting instant, the atmosphere shifted.
"...A demon?"
Almost instinctively, the swordsman's eyes narrowed, and a faint trace of killing intent surfaced. Yet just as quickly, it faded, replaced by a laugh as he looked at Soma—standing plainly beneath the sunlight, his shadow cast clearly upon the ground.
"Sir, you must be joking," he said, shaking his head with amusement. "Where would demons even come from in this world? Or… have you actually seen one? If so, perhaps you could tell us more?"
"I've only heard others say that demons exist," Soma replied calmly.
"Then that must be nothing more than rumor," the swordsman said firmly, his hand unconsciously resting on the hilt of his blade. "There are no demons in this world. And even if there were… they would be wiped out soon enough. There are those who dedicate themselves to protecting humanity, who would hunt down every last one of them."
There was conviction in his voice—unyielding, absolute.
"I suppose you're right," Soma said softly. "How could there be demons in this world?"
And then—
He burst into laughter.
Not a quiet chuckle, but a deep, unrestrained laugh that bent his body forward, as though the absurdity of it all had become too much to bear.
The swordsman frowned slightly, utterly bewildered. His companions exchanged glances, equally at a loss.
"...We still need to find our companion," the swordsman said at last, forcing an awkward smile. "We won't trouble you any further."
With that, he quickly led the others away.
Only when they had put some distance between themselves did one of them murmur under his breath, "Could he be… a lunatic?"
"Looks like it," another replied quietly.
Soma remained where he stood, watching their retreating figures.
He lifted the flask to his lips and took a long drink. The liquor burned fiercely down his throat, like fire spreading through his veins, yet it only seemed to make him laugh harder.
He wanted, in that moment, to shout after them—
Have you ever seen a demon walking beneath the sun?
But he didn't.
Instead, he simply stood there, laughing freely, the sound echoing across the quiet mountains.
Behind him, Kanao tilted her head, watching her uncle with puzzled curiosity. She didn't understand what was so amusing—but seeing him laugh like that, she couldn't help herself.
She scratched her head lightly, then let out a soft, innocent giggle of her own.
"Hehe… hehe… hehe…"