The battle raging alongside the train had never stopped.
But the two sides fighting were now in very different conditions.
Tanjiro's recovery had slowed drastically. His uniform was torn to shreds, and he knelt off to the side, repeatedly vomiting blood. Not a trace of rationality remained in his eyes.
Even so, he still stubbornly tried to rise and attack Akaza.
Rengoku's white haori was also stained with blood and dust. The wound at his temple had bled so heavily that his vision was nearly dyed red. He was clearly exhausted now, his breath coming in heavy gasps.
Compared to the two of them, however, Akaza looked completely at ease. Though dust clung to his body, the wounds he had suffered were already regenerating at a rapid pace.
Nezuko and the others, having finished treating the injured, now stood at the edge of the battlefield with their blades drawn.
Yet none of them stepped forward to help.
It wasn't because they didn't want to.
They understood one thing clearly: if they couldn't keep up with the speed of the battle, rushing in would only get in the way and break the flow of the fight.
"Hey, Kyojuro," Akaza said.
He made no move to attack. Instead, he simply waited for Tanjiro to recover, giving Rengoku time to steady his breathing.
"Haven't you realized it yet? Humans are far inferior to demons."
He gestured toward Tanjiro.
"Just look at that boy. I can break his limbs. I can smash his body apart. And he still stands back up."
Akaza's gaze shifted back to Rengoku.
"But you're different. Your injuries are piling up. Your vision is failing. Your ribs are shattered. Even your internal organs are damaged."
He smiled faintly.
"If this keeps up… you really will die."
Rengoku glanced sideways at Tanjiro, who struggled to stand—only to collapse again.
He slowly exhaled.
"So what?"
"Can't you see the superiority of demons?" Akaza stepped forward, unable to hold himself back any longer. "Then become one. Accept it already!"
"No matter how desperately humans struggle, they are destined to lose against demons! Haven't you realized that yet?!"
"I am a Hashira of the Demon Slayer Corps." Rengoku tightened the muscles around his wounds and raised his stance once more. "I will fulfill my duty."
His voice remained unwavering.
"I will protect everyone. No one will die here today."
"Ahh…" Akaza's smile widened as luminous blue snowflake patterns once again spread beneath his feet.
"What perfectly refined fighting spirit. An ordinary person would have collapsed long ago with injuries like these."
"As expected, Kyojuro—you should become a demon," Akaza continued. "Then you could fight me like this forever. For someone like you to die would be such a waste."
Just as the two were about to clash again, a sharp sound tore through the air.
A crimson streak shot in from nowhere, heading straight for Akaza. Sensing the deadly threat, he had no choice but to dodge.
A thunderous explosion followed.
Dust and debris blasted upward, swallowing the battlefield in a thick cloud.
The sudden disturbance made the four watching nearby tense instantly.
Zenitsu was the first to turn around. That familiar, terrifying sound was coming from behind them—and it was getting closer.
[ It feels even more terrifying than before… and so chaotic… what's going on?]
"What?" Takeo looked around, the veins in the hand gripping his sword bulging. "Is there another enemy?"
"No… not an enemy," Zenitsu said, pulling his gaze back toward the battlefield. "Probably…?"
"Zenitsu, why are you talking so strangely?"
"Stop nagging!" Zenitsu shouted. "You have no idea what kind of pressure I'm under right now! Seriously—why am I the only one who knows?! This is way too cruel!"
They were about to ask more questions when heavy footsteps suddenly sounded behind them.
All four spun around at once, gripping their weapons tightly.
But the moment they saw who it was, every one of them froze.
Nezuko covered her mouth, her voice trembling.
"…Mr. Hiru?"
The Hiru standing before them looked nothing like his usual gentle self.
Demon horns. Sharp fangs. Clawed hands. Pale skin. Eerie gray-blue patterns spreading across his body.
Everything about him declared the same thing—the figure before them was no longer human.
Even his gray eyes had changed. Within them now lay cross-shaped pupils no human could possess.
Hiru let out a slow breath.
A short spear rested in one hand, while the other casually tossed the empty weapon box onto the ground beside the children.
"I'll explain everything when I get back," he said calmly. "For now, the only problem left is that Upper Moon… right?"
"Yes—yes!" Nezuko swallowed, forcing down the instinctive trembling rising from deep within her. "Mr. Rengoku and my brother have been holding that demon back, but my brother's condition is very strange!"
Hiru nodded and turned his gaze toward the battlefield as the dust gradually cleared.
"Tanjiro, huh? Got it."
He glanced back at them.
"Just make sure you all stay safe."
Meanwhile, at the center of the battlefield, the sudden attack had forced both Akaza and Rengoku to stop.
As the dust slowly settled and the weapon embedded in the crater came into view, the two reacted very differently.
Rengoku's expression brightened, his spirit visibly reignited.
Akaza, on the other hand, looked deeply annoyed.
"You again… you meddlesome bastard."
"Yeah, yeah—me again." Hiru walked up behind Rengoku. "How bad are your injuries?"
"I'm fine. I can still fight!" Rengoku's gaze shifted slightly as he looked at Hiru more carefully. "So this is the demon transformation Father once mentioned? Hmm… truly difficult to distinguish!"
"Difficult to distinguish?" A vein bulged on Akaza's forehead as he pointed directly at Hiru, his expression twisting with malice. "Kyojuro! You've been deceived by this guy! He's a real demon!"
But Hiru ignored him completely.
Instead, he looked at Rengoku.
Despite being covered in wounds, the Hashira still seemed eager to fight at his side.
Hiru raised a hand to stop him.
"You know," he said slowly, "every time I run into you while you're dealing with demons, things somehow become unbelievably troublesome."
He paused, then added with a sigh,
"But then again…"
"Mmm? But what? Don't worry about me! I'm completely—"
Hiru mercilessly jabbed a finger straight into Rengoku's wound.
"Ugh!"
Rengoku flinched, yet still tried to maintain a brave face.
Seeing that, Hiru's expression only grew more complicated.
"You're this badly injured and still trying to act tough?" he said flatly. "Go rest. Now. Immediately."
He glanced at him with faint irritation.
"The entire Rengoku family really was born just to counter me, weren't they?"
Rengoku tightened the muscles around his wounds with his breathing technique, clearly preparing to argue—
But Tanjiro, whose injuries were already recovering, suddenly rushed past him and attacked Hiru without hesitation.
Hiru sidestepped the strike and grabbed Tanjiro by the back of his collar.
"And you Kamado family too," he muttered. "Were you all born specifically to mess with me?"
But Tanjiro couldn't hear a word.
He struggled relentlessly, trying to attack Hiru again and again.
"That's enough. Quiet down."
Hiru pressed Tanjiro's head downward—then suddenly drove his knee upward into Tanjiro's forehead.
"There's no time to deal with your prob—OUCH!"
A sharp crack of bone echoed.
Tanjiro's forehead remained completely unscathed.
Meanwhile, faint blood slowly seeped through the fabric at Hiru's knee.
"This is going too far! Seriously too far!"
Hiru twisted his wrist, pinning Tanjiro down before striking the back of his neck.
This time, Tanjiro finally went limp.
Even so, Hiru couldn't help clutching just above his knee.
"Even for a demon," he muttered in disbelief, "bones shouldn't be this hard."
Akaza watched as Hiru knocked Tanjiro unconscious and casually tossed him toward Kyojuro. A vein pulsed faintly on his forehead.
"Hey, hey," he said slowly. "Your sympathy for humans is a bit excessive, don't you think?"
His gaze hardened.
"And you're Kokushibo's brother. Honestly… you're embarrassing him."
"Hah—what, jealous that I have an older brother?"
Hiru let out a long sigh and lifted his gaze toward Akaza.
"What, did you go home and train your speaking skills or something? Trying to win back a little pride in that department?"
He tilted his head slightly.
"I'm not naïve enough to try settling scores with you in combat right now. But you—a brute like you—actually think you can challenge me in a battle of words?"
Nearby, Kyojuro stood holding the unconscious Tanjiro in his arms.
He watched Akaza silently.
The demon who had been relentlessly trying to persuade him earlier now stood there with clenched teeth, the muscles in his cheeks twitching.
Hiru, however, showed no intention of stopping.
"But thinking you could provoke me with something like that is pretty naïve," he continued, resting his weapon across his shoulder.
"That's nowhere near enough."
He gave a small shrug.
"Why don't you just accept Doma's goodwill and become friends with him? You could learn quite a bit about conversation from him."
Then his tone turned mockingly casual.
"And besides, you're both going to hell anyway. If you build a good relationship now, the journey later won't be so lonely."
"The one who should be going to hell is you," Akaza snapped. Veins bulged along his cheeks again.
"You still don't understand, do you?"
His voice dropped lower.
"Kokushibo returned even the last of that man's blood. That proves he doesn't care about you at all—not even a little."
"To him… you're nothing."
"Yeah, I know," Hiru replied calmly, completely unmoved.
"After all, he even traveled a long way just to find me because of the nonsense Doma told him."
Hiru scratched his cheek casually.
"He wanted to ask about my sexual orientation."
The smile on Akaza's face froze instantly.
But smiles don't disappear.
They just move.
And now—
it was Hiru who was smiling.
"Sorry about that," he said lightly. "My big brother might care about me more than you think."
He tapped his chin as if recalling something.
"And I also learned quite a few things about you."
"Let me think… ah, right."
"Apparently you've always been strangely devoted to women."
"You've secretly helped them many times."
Hiru's smile widened slightly.
"Wow. Our Akaza is really kind, isn't he?"
"Even though he's a man-eating demon… he's especially tolerant toward women."
He paused for a moment before continuing.
"Could it be that when you were human, you secretly loved someone?"
"And you still can't forget her… so you keep helping women who resemble her?"
His voice turned softer—but the words cut deeper.
"If that's the case, then Akaza…"
"Your love for her is really quite shallow."
Akaza slowly narrowed his eyes.
A brilliant blue, snowflake-like pattern spread beneath his feet as a nameless anger began to rise within him.
"Nothing but pointless words…" he said coldly.
"Even the former Upper Moon One has completely fallen."
A former Upper Moon?
Kyojuro froze and instinctively turned to look at Hiru.
[ I've heard that Hiru and Yoriichi have an older brother who became a demon… but an Upper Moon?]
According to the records kept by the Rengoku family, the Demon Slayer Corps hadn't slain an Upper Moon in over a hundred years.
If Upper Moon One had truly been replaced, there was no way such information could have remained hidden for decades.
Hiru glanced at the stunned expression on Kyojuro's face and immediately realized what it meant.
So the Rengoku family really does keep records about the Twelve Kizuki.
He let out another long sigh. The words he had originally been about to say changed before they left his mouth.
"My brother did tell me quite a lot," he said at last. "But I can't agree with your claim that he's fallen."
[ Does that mean… Hiru is actually admitting it? Then Yoriichi also—]
[ No. That can't be right.]
[ Demons shouldn't be able to move under sunlight. And wisteria should—]
"Kyojuro."
Hiru's calm voice cut through his thoughts.
"I know what you're thinking. But it's true."
He paused briefly.
"And the Master knows about it."
Kyojuro's head snapped up.
"…The Master knows?"
"Yeah. He knows."
Hiru watched as Kyojuro instinctively stepped half a pace back.
"To be honest, I'm tired of keeping up the act anyway. At the next Hashira meeting, I'll explain everything to everyone."
He waved his hand lightly.
"So don't worry about it right now. Go get some rest over there. If you want the details, I'll explain them later."
However, Hiru had clearly underestimated just how shocking this revelation was for Kyojuro.
The veins along Kyojuro's arm bulged as he held Tanjiro. His voice dropped lower.
"…Why did you choose to become a demon, Hiru?"
"Hm… you probably won't believe it," Hiru said with a quiet sigh.
"But I did it because I wanted to kill myself."
He raised a hand and gestured toward Akaza, who had already assumed a combat stance.
"Anyway, I'll explain everything properly later."
His tone grew more serious.
"For now… could you give me some time alone with Akaza?"
"If we really fight, he'll lose. But I'll be beaten pretty badly before I manage to wear him down."
"And by then, I won't have the energy left to worry about you."
He glanced toward the distance.
"So could you stay as far away from us as possible?"
Kyojuro stared at him in silence for a long time.
Eventually, the tension in his arms slowly faded.
"…Understood."
"I'll wait patiently until then."
"What a headache…" Hiru muttered, scratching his hair with his free hand and letting out another sigh.
Then he looked toward Akaza with mild exasperation.
"Seriously. Thanks to you, I'm going to have a mountain of trouble waiting for me when I get back."
"I really let my guard down this time."
"So you've developed feelings for these humans?" Akaza said coldly.
He made no move to stop Kyojuro from leaving, his gaze remaining fixed on Hiru.
"You haven't stayed among humans so long that you've actually started believing you're one of them, have you?"
"Humans are destined to grow old and die. They simply can't compare to demons."
"Enough with the 'humans this, humans that.' Stop looking down on them," Hiru replied casually.
"Humans are far more impressive than demons."
He tilted his head slightly.
"Do you know what kind of situation Muzan once ran into?"
"Calling humans weak… Muzan would cry if he heard you."
Akaza, who had been about to attack, suddenly stopped.
"What nonsense are you talking about?" he said, frowning. "How could that man possibly lose to a human?"
"Ah… that makes sense."
Hiru's lips curved into a wicked grin.
"Of course he wouldn't tell you."
He took a few slow steps forward as he spoke.
"After all, he barely managed to escape—even after splitting himself into more than eighteen hundred pieces."
Hiru shrugged lightly.
"Honestly, it was pretty pitiful."
His smile widened a little.
"Though thanks to him, I don't really lack red paint anymore."
Akaza's expression darkened.
"…Are you saying all this just to stall for time?" he asked coldly.
"Do you really think dragging things out with meaningless chatter will let you beat me?"
"Of course not."
Hiru continued walking toward him.
"I'm not very good at fighting."
He stopped where one of his weapons had landed and bent down to pick up the other short spear.
"But there's only about an hour left until dawn."
He straightened slowly.
"No matter how much you stall, you won't be able to fight me until then."
A faint smile appeared on his face as he raised the spear and pointed it toward Akaza.
"Because you and I aren't the same."
For a brief moment, silence filled the battlefield.
Then Hiru spoke again.
"Sunlight won't protect you."