After returning, Hiru avoided the others and spoke privately with Yoriichi once more. Not long after, a letter arrived from Uzui, and he left in haste.
True to his word, Yoriichi remained behind. He personally guided the Musou twins and the Kamado family in their training. Yet it did not take long for him to notice that Muichiro's thoughts were clearly elsewhere.
As expected, once his injuries had fully healed, Muichiro slipped away again.
Yoriichi did not intervene. Instead, he concealed his presence and followed at a distance. He watched as Muichiro sought out Kokushibo, hoping for a different answer—only to be met with an even crueler truth. Muichiro stood frozen, his thoughts in turmoil.
But the daze did not last.
Before long, Muichiro steadied himself. His expression hardened with resolve as he said something to Kokushibo.
Kokushibo was briefly taken aback, then a faint, satisfied smile curved his lips. He said nothing. He simply raised a hand and lightly tapped Muichiro on the forehead.
As though he had received the answer he sought, Muichiro smiled again, then took his leave.
Yoriichi's gaze lingered for a moment on Kokushibo's face—the face so strikingly similar to his own. His lips pressed into a thin line before he turned to go.
"You're nearby, aren't you?"
Yoriichi halted mid-step and turned back toward Kokushibo.
"I heard from Hiru. And yet you hesitated…" Kokushibo's eyes faced his direction, though they did not focus on anything in particular. "…A needless delay."
Yoriichi remained silent, standing where he was.
"You and I should have fought four hundred years ago," Kokushibo said as he turned and walked toward the cave. "Do not make me wait in vain for an ending that has already been decided."
Yoriichi quietly clenched his fist. After a soft sigh, he turned and walked in the direction Muichiro had gone.
[An ending already decided…]
When he had last crossed blades with Kokushibo, Yoriichi had already grasped the extent of his brother's strength. Had it been during his years as a human, they might have stood evenly matched. But now—having become a demon, having trained unceasingly until countless techniques had fused into his bones and become instinct—
At the thought, Yoriichi let out another faint sigh and followed after Muichiro.
[It seems the one who has failed to let go… is me.]
…
After returning, Muichiro said nothing about the encounter. Instead, he threw himself into training with even greater focus, much to the astonishment of Aoba, who had been tagging along to observe.
Yet when Yukinashi excitedly mentioned Muichiro's progress to Yoriichi, Yoriichi merely looked surprised for a moment before nodding as though it were only natural.
That calm acceptance of talent left Yukinashi visibly deflated.
"Honestly—someone favored by the heavens like you is impossible not to envy. I wish I had that kind of gift."
"Is that so?" Yoriichi looked faintly embarrassed. "I've never paid much attention to such things… I'm sorry."
"What are you apologizing for?" Aoba sat down nearby and glanced toward the four still sparring on the training grounds. "But what about you? Have you run into something lately? Your blade's been… hesitant. Or maybe that's just my imagination after spending too long as an instructor. I'm not as strong as you, after all."
"No. There are indeed matters that have slowed me… You're perceptive, Yukinashi."
Aoba burst into laughter.
"Well, I have to be. My strength isn't anything special. If I'm not sharp-eyed, what can I teach the kids? It'd be embarrassing if they surpassed me in everything."
Yoriichi simply smiled.
"I won't try to guess what's troubling you. Even if I guessed right, I doubt I could help." Yukinashi tilted his head toward him. "All I can say is—sometimes letting things take their natural course isn't a bad thing. It might turn out to be the best outcome for both sides."
"Letting things take their course…" Yoriichi lowered his gaze, his thumb brushing lightly along the hilt of his sword.
[I doubt it will be that simple.]
"By the way… how's your disciple? He hasn't crossed any lines, has he?"
Yoriichi blinked. "Kamado Tanjiro? Hmm… How should I put it? He's even more gifted than I expected. He's managing both the development of his Blood Demon Art and the restraint of his urges remarkably well."
"Remarkably well, huh… That's almost frightening." Aoba picked up a twig and idly traced lines in the dirt. "Sometimes I wonder—if demons could restrain themselves, communicate, and refrain from eating people… then what exactly are we killing? Demons, or humans? In that case, are they the demons—or are we?"
He paused, then chuckled.
"But when you think it through, that line of reasoning falls apart. There's no shortage of people in this world who 'devour' others. What we do simply demands greater strength. In essence, it's not so different from the Police Department."
"And if you take it one step further, perhaps we of the Demon Slayer Corps are the true anomalies in this society. Hahaha—"
Yoriichi looked at him. "Why do you say that?"
"Well—demons eat people because they're driven by the Demon King and their instincts. But we're different. Everything we do comes from our own will."
Yukinashi stared at the shallow groove he had carved into the dirt, the smile on his face unusually calm.
"Some of us join because our families were slaughtered. Some seek fame. Others simply crave battle. To fight demons, we temper ourselves without rest. After passing the trials, we seek out man-eating demons and cut them down.
"Those demons may look grotesque, but most still wear human faces. Many even retain fragments of their humanity—some are handsome, some almost cute. Yet any Swordsman who has passed the Final Selection can strike them down without hesitation.
"Yes, people in society 'devour' one another too—but it happens quietly. It isn't as overt as what we do. And the Police Department, tasked with maintaining order, does everything it can to prevent bloodshed.
"In contrast, we see blood nearly every day. We live on the boundary between life and death. In that sense, we're not so different from demons who leave trails of murder in their wake. We are anomalies.
"And there are Swordsmen who, when facing demons far weaker than themselves, choose to torment them before killing them—then smile in satisfaction. Sometimes I worry that if such Swordsmen retire without something to ground them, they might become new 'demons' themselves."
He waved a hand dismissively.
"Ah, don't take my rambling too seriously. Demons won't disappear anytime soon. It's just idle speculation."
Yoriichi had noticed the solemnity in Aoba's expression as he spoke. These were not careless words. He had clearly given them serious thought.
And that realization made Yoriichi understand just how different this era was from his own.
In the chaos of the Warring States period, it was unusual for a man not to know martial skill. A warrior who had never slain marauding bandits would be looked down upon. Even common folk carried blades, ready at any moment for bloodshed.
But this age was different.
People lived in peace. Society prospered. Even criminals were pursued, apprehended, and rehabilitated—rather than cut down where they stood. There was even a newly enacted sword ban.
[Yes… what this era needs is stability.]
Yoriichi tightened his grip on the hilt and let out a slow breath.
"Thank you, Yukinashi."
"Huh? Thank me for what? Hey—don't take my complaints as advice. If you start acting on them, I'll never hear the end of it from the younger generation."
Yoriichi only chuckled softly and shook his head. His gaze drifted back to the four still training earnestly.
"I simply think… this world truly does need stability. At the very least, children shouldn't be the ones forced to bear this burden."
"…Yes." Aoba looked on as well, smiling faintly. "I just hope they can all grow up safe and sound."