Ever since Doma came to visit, Kokushibo had been reflecting on his life.
He came to realize that, in the end, it had been a failure.
When he was human, he resented how his father constantly compared him to Yoriichi. That jealousy slowly consumed him, driving him to abandon his family and join the Demon Slayer Corps after meeting him again.
He chased after him relentlessly, only to be cast back down every time he thought he was getting closer.
Those who awaken the Slayer Mark do not live past twenty-five.
The words lingered in his mind like a curse. It was the prime of a swordsman's life, yet he was destined to die just as he reached his peak.
He refused to accept it.
So after his defeat by Muzan, he accepted the offer and became a demon.
After that, he severed his ties to humanity—and, at the age he should have died, cut himself off from the Corps as well.
Yet he never imagined that Yoriichi wouldn't die at twenty-five.
Not only that, he later encountered Muzan and severely wounded him, forcing him into hiding until news of Yoriichi's death reached him.
He had thought he would never have another chance to surpass him. Yet, by a twist of fate, he encountered Hiru—and felt both joy and bewilderment.
What Muzan had sought for a thousand years without success, he had achieved.
How ridiculous.
Those with the Slayer Mark weren't supposed to live past twenty-five—yet Yoriichi did.
Demons weren't supposed to walk in the sunlight—yet Hiru did.
Kokushibo could only sigh at the irony of it all.
But Yoriichi, just as he had in the past, yielded to him at every turn. Though he had the power to kill him on two separate occasions, he held back once and avoided the confrontation the other.
It was from Hiru that Kokushibo truly sensed killing intent. Even though he had started calling him "brother" and had grown somewhat closer, Kokushibo was certain that the moment an opening appeared, Hiru would strike without hesitation.
He knew full well that the conflict between them was irreconcilable. Of the three, only Yoriichi still naively hoped to salvage everything.
At that thought, Kokushibo frowned slightly and looked up at the moonlight streaming through the cave entrance.
"It seems there won't be any tonight either… Hmm?"
Though the scene outside the cave appeared unchanged, Kokushibo sensed something was off. He picked up the long sword beside him, rose to his feet, and walked slowly toward the entrance.
The night air was clear, and the full moon hanging high above lit the forest almost like daylight.
As his view opened, he saw a figure in a red haori standing among the trees. His grip on the sword tightened slightly.
"…You've come."
At the sound of his voice, the figure—who had been gazing up at the full moon—turned around.
His white hair, rimmed in silver by moonlight, shifted as he moved, deepening into a rich crimson.
"…Brother."
"It's been a long time since I've seen you like this," Kokushibo said calmly. "Compared to that unsightly uniform, this suits you better."
He wasn't wearing the Corps uniform. Instead, he had on a yellow kimono with black hakama, draped in his familiar red haori.
At those words, Yoriichi's left hand tightened slightly around his scabbard.
"…Yes. It has been a long time."
Kokushibo glanced at the rising moon and drew the dark red blade from his waist.
"It's good that you came to find me so quickly after making up your mind… I've been looking forward to this."
"…No, Brother. I haven't made up my mind."
Yoriichi raised a hand and pushed aside his mask. The flame-like Slayer Mark appeared on his face once more, his crimson eyes filled with sorrow.
"I simply… don't have time to hesitate any longer."
Seeing that weakness on a face identical to his own, Kokushibo's frown deepened.
"Are you afraid of the final battle with Muzan? To you, he's nothing more than a defeated foe, isn't he?"
"No. Even when I was human, I never feared Muzan."
Yoriichi drew his sword, but let the tip hang downward instead of pointing it at him.
"I've only just realized my own weakness. Whether in the past or now, I've always tried to avoid things… but some matters won't disappear just because I turn away from them."
"Just a few days ago, Hiru's identity as a demon was exposed, and the Corps convened a Hashira Meeting because of it."
Kokushibo paused slightly, his gaze dropping once more to his attire.
"So that's why you're dressed like this… You've been expelled from the Corps?"
At that moment, Kokushibo saw the blade—black as obsidian—flare into a vivid crimson.
"That's not the case," Yoriichi said in a low voice. "We're still part of the Corps."
Sensing the shift in his aura, Kokushibo lowered his blade.
"Is Hiru planning to sacrifice himself to stabilize morale?"
Yoriichi did not answer. The red glow of his blade only grew more intense.
"So you intend to end everything quickly and withdraw from the Corps with him?" Kokushibo lifted his gaze. "Naive."
Yoriichi lowered his head.
"All things have their time… Even demons must one day come to a natural end, don't they?"
"And you intend to save everyone under such circumstances?"
"…"
"Yoriichi Tsugikuni… you think too highly of yourself."
Yoriichi raised his head and met Kokushibo's calm gaze. He opened his mouth several times, but in the end, only a hoarse apology came out.
"I'm sorry."
"Do you think Hiru would thank you for letting him live?" Kokushibo frowned. "He has always had a clear goal. Whether human or demon, he sees the world more clearly than either of us and knows exactly what he should and shouldn't do."
"Even when he hesitates, he still shows unwavering killing intent when facing me… Once he achieves his goal, he'll choose to bring about his own end."
"…No. I'll stop him."
"Then you'll have to become his enemy," Kokushibo said calmly. He didn't raise his blade—only watched him. "And becoming his enemy is simple—you just have to kill the people he values and protects."
"But even your decision to kill me relied on outside pressure… Hah. Yoriichi Tsugikuni—you truly are as repulsive as ever."
Yoriichi opened his mouth several times, but no words came.
Because he had spent so long by Hiru's side, he knew that everything Kokushibo said was true.
He couldn't stop him.
Seeing his tense expression, Kokushibo raised his long sword again and pointed it directly at him.
"Yoriichi Tsugikuni—if you've truly made your decision, then cut off my head cleanly today. Show me whether you're merely speaking empty words."
At last, Yoriichi raised his Nichirin Blade—now completely crimson—and pointed it at him.
"…I will."