"What an incredible power," Hiru murmured, feeling the strength coursing through his body. "It's no wonder someone would lose themselves in this after obtaining such power… But is it really worth denying all your past efforts just to surpass one person?"
Hiru still couldn't understand his elder brother—no, Kokushibo's thoughts. But at the moment, something far more pressing demanded his attention: dealing with the demons that had come to attack him. Looking at the demons crawling on the ground, he frowned slightly, wondering how best to kill them.
Until now, he had always dragged them outside, cutting off their limbs one by one until sunrise, letting the sun burn them to ash.
The problem now was that he had become a demon himself—and sunlight was deadly to him.
Yet if he simply let these demons escape, the villagers nearby would surely suffer.
[If only they could just die on their own.]
A fleeting thought crossed his mind, and even he found it absurd—no one would willingly die in the middle of a fight.
But to his shock, the moment the thought of killing them formed, several dark shadows suddenly lunged from behind the demons. The shadows, far more terrifying than the demons themselves, tore them apart in an instant.
The shredded demon flesh turned to ash and merged into the shadows. Then, the shadows gathered together, forming a small black gem—slightly larger than a grain of rice—that dropped onto the ground.
[What… just happened?]
Hiru's eyes widened in disbelief.
[Did I… do that?]
But before he could investigate further, a wave of weakness washed over him. The hunger in his stomach grew unbearable, the urge to destroy intensifying along with it.
Glancing at the full moon hanging high in the night sky, he stopped thinking and picked up the tiny black gem, tucking it away. Avoiding the wisteria blooming behind his house, he stepped into the mountain forest.
The hunger was driving him insane. But demons could only replenish energy through blood. Unwilling to harm humans, he had no choice but to hunt animals.
"My body feels so light, and my strength has increased so much," Hiru murmured, marveling at the changes. "Aside from fearing sunlight and enduring hunger, demons must be the perfect beings that emperors throughout history dreamed of becoming.
Still… were those demons I fought really that weak? I'm a newborn demon, and theoretically, demons grow stronger the more humans they consume, don't they?"
What he didn't know was that by transforming himself through his own drug, he hadn't become an ordinary demon—but a Demon King.
Even as a newly born Demon King, he possessed absolute dominance over lowly demons who hadn't even devoured ten humans.
"So hungry…" Hiru clutched his stomach, glancing around. "Didn't the villagers mention wild boars on this mountain? I wonder if one boar's blood could fill me up? Damn… I'm so hungry I can't even think straight.
Come out, wild boar. Hurry. I promise I won't make it hurt too much…
Ugh—this is bad. My head is full of nothing but kill, kill, kill…"
...
When Tsugikuni Yoriichi heard the news brought by a Demon Slayer, he froze. "The Tsugikuni Clan… annihilated?"
"I truly sympathize with you!" exclaimed the man with golden hair tipped in brilliant red. "But please, don't let sorrow consume you! Those who linger in the past cannot move forward! So please, rise above this shadow!
You still have your younger brother—and there are so many demons in this world! Find him, bring him close, teach him! You're so talented—surely your brother will become a fine swordsman too!
Then, when the time comes, join the Demon Slayer Corps together! We can slay demons side by side!"
"Thank you, Mr. Rengoku. But as for joining the Demon Slayer Corps, I'd like to think about it first," Yoriichi said quietly, gripping his scabbard tightly.
He had stayed out of the Corps for his brother's sake, wandering to hunt demons on his own. That life without a fixed home meant he only learned of his clan's destruction nearly two years after it happened.
"You have news of my brother?"
"I've heard from fellow swordsmen!" the man—Rengoku—replied in his booming voice. "There's a kind gentleman near Rakusha Mountain who helps Demon Slayers!
As payment, he only asks that, when possible, they capture demons alive—and later assist him in killing them however he chooses! A strange man, but truly kindhearted!"
Yoriichi tried to recall his brother's face, but all that came to mind was a small boy crying in fear after witnessing their mother's anger—and later, a gentle yet unfamiliar man glimpsed by chance on a visit home.
Would his brother even remember him? He had been only four when Yoriichi left, and when Yoriichi returned by coincidence years later, the boy had already grown up.
What if he saw me as an ill omen too, and avoided me?
Just like my elder brother… Even though he joined the Demon Slayer Corps to fight demons, after awakening his mark as I taught him, it was as if he became a different person. The way he looked at me was always filled with resentment.
Yoriichi sighed, troubled. Still, he decided to go to Rakusha Mountain to find his brother. If his brother didn't want to see him, he would simply leave again.
Though… my elder brother has probably already heard of this before I have.
As he drew closer to Rakusha Mountain, Yoriichi began hearing more news about his brother. Learning that Hiru, too, was looking for him brought a quiet warmth to his heart.
But when he followed the clues and arrived at the small house late that night, he found it empty—and filled with the scent of demons.
Yoriichi's expression hardened as he searched carefully through the house. There was only one sign of departure, but no traces of blood.
That meant his brother was still alive.
Good. At least there's still hope.
Yoriichi tightened his grip on his sword and quickened his pace.
...
"Still not enough… If I were human, I wouldn't even think of drinking raw pig's blood, and this much would have been impossible to finish. Yet now that I'm a demon, I drank all of it—and I'm still hungry…" Hiru wiped the blood from the corner of his mouth. "This appetite and digestion… this can't be good. Will I end up starving to death?
Even if I do, I have to hold on until I see my brother. I need to tell someone I trust that our eldest brother became a demon…
Ah—though now I'm a demon too. I wonder, will he strike me down on sight? Will I even have a chance to speak?"
Hiru stood, stepping around the wild boar he'd drained to a husk, and prepared to hunt more beasts under the cover of night.
"Hiru?"
The voice behind him froze him in place. He turned instinctively—and saw a tall swordsman, his face marked with vivid crimson lines. Those red eyes overflowed with disbelief and fury, yet his face was achingly familiar.
It was his second elder brother—Tsugikuni Yoriichi.
"...Brother." Hiru stopped and let out a bitter smile. Fate truly had a cruel sense of humor. "If you'd come just a little sooner, you might have seen my last moments as a human."
"You became a demon tonight?" Yoriichi's grip on his scabbard tightened until veins stood out along his arm. His voice trembled with rage and sorrow. "Have you eaten… killed anyone?"
"To be honest, this boar was my first prey," Hiru said, sitting down with a faint smile. He truly didn't mind dying at his brother's hand. "I know, as a Demon Slayer, you should kill me now—but please, let me speak first, Brother."
Yoriichi stepped closer, stopping before Hiru, his expression shadowed and unreadable. "...Speak."
Hiru told him everything—about Michikatsu's departure, his return as a demon, and his own eventual transformation.
"If only I'd noticed the message you were trying to send earlier… if only I'd come back sooner," Yoriichi whispered, one hand clutching his scabbard while the other brushed the hilt of his blade. "Then you wouldn't have become a demon."
"Please don't blame yourself," Hiru said softly, smiling faintly. "It wasn't your fault. And if I can end my existence at your hands, perhaps that's its own kind of mercy. It's just…"
"Just?" Yoriichi lifted his head. His handsome face was filled with sorrow.
Hiru's smile deepened slightly as he looked up at his brother. "It's just… I'm terribly afraid of pain. So, if possible—Brother, could you end me gently?"
But then, the sound of something falling drew Hiru's attention.
The mighty, beautiful swordsman—who had always seemed like a god descended to earth—was silently weeping.