Akaza could only watch as the charging youth knocked Hiru out of the gate's range, while he himself plunged down into the castle.
What infuriated him the most was the look on Hiru's face as he was sent flying away. It was even more shocked than Akaza's own—and there wasn't the slightest trace of relief at being saved.
Instead, it was filled with the bitter frustration of a plan that had just fallen apart.
[That bastard was acting the whole time, even in that situation?]
Veins bulged across Akaza's forehead.
[Thinking about other things in the middle of a fight… That guy really deserves to be cut into a thousand pieces.]
As the sound of the biwa echoed through the air, the weightless sensation of falling vanished. Akaza's feet touched solid ground once more.
The moment he saw who stood before him, Akaza immediately dropped to one knee.
"My Lord."
Muzan stood there in a perfectly tailored suit, fury burning plainly in his crimson eyes.
"Akaza," he said coldly. "Do you have anything you wish to say in your defense?"
"My deepest apologies."
"As an Upper Moon, you couldn't even kill a single human?" Muzan's voice grew colder with each word. "Are you telling me the Upper Moons are no different from the Lower Moons—that your existence serves no purpose at all?"
As his words fell, large cracks began spreading across Akaza's body. Bright red blood seeped steadily from his seven orifices.
Yet Akaza remained kneeling respectfully, his head bowed, allowing the wounds to spread across his body without resistance.
"I am deeply disappointed in you, Akaza!" Muzan's voice rose sharply. "You and Doma both! Ever since Kokushibo left, not one of the six Upper Moons has proven capable of actually serving me! And that idiot Gyokko even managed to get himself killed by that irritating puppet!"
A deafening boom echoed through the hall.
A whip-like tendril lashed out from behind Muzan and sent Akaza flying across the room. Yet the moment he hit the ground, he immediately knelt again, lowering his head even further.
"…My deepest apologies."
"Apologies?" Muzan's expression twisted with rage. "You and Nakime clearly had the chance to drag that puppet into the castle. Why did you fail? Why didn't you eliminate those irritating human vermin first?"
"Akaza, your incompetence surpasses even my expectations—"
His voice suddenly stopped.
For a moment, the hall fell silent.
Then Muzan erupted in even greater fury.
This time, the pressure did not fall on Akaza alone—Nakime, seated to the side, was also affected. Blood began seeping from her nose and mouth.
"Why?!" Muzan roared. "Why has another demon that conquered the sun appeared?! What the hell have you useless creatures been doing?!"
"First that damned puppet, then that brat who learned Sun Breathing! One after another—"
Muzan's gaze snapped toward Akaza.
Grotesque crimson flesh suddenly swelled and spread along his arms. Jagged fangs sprouted from the ends and clamped directly onto Akaza's body.
Muzan's face twisted into something feral.
"Do you know what just happened?" he hissed. "That brat you let escape—he also conquered the sun!"
"Akaza! Akaza! Akaza—!" His voice grew harsher with each repetition. "How can you be this useless?! Why do you keep missing these opportunities again and again?! I even erased the memories that would hinder your progress! So why do you still manage to disappoint me this badly?!"
[Erased… memories?]
[Did I forget something?]
But Muzan paid no attention to his thoughts.
He flung the Upper Moon aside like trash and strode straight toward Nakime. His fingers dug into the crown of her skull as he forced more blood into her body.
"Forget about that swordsman who keeps attacking the castle! Expand it further! Find the headquarters of the Demon Slayer Corps!
"That irritating Ubuyashiki must know where that puppet and that brat are! Find them all!
"And Hantengu and Daki! Get those useless fools moving too! Scatter every demon we have!
"I will wipe out the Demon Slayer Corps—and those two irritating pests—completely!"
...
Unaware of Muzan's furious outburst and everything that followed, Hiru had already finished re-treating Kyojuro's wounds and confirming that no lasting damage remained.
With that done, he unceremoniously dumped the remaining mess onto the Flame Hashira and immediately set off with Tanjiro toward Tamayo's residence.
Tanjiro regained consciousness along the way.
Because he still remembered everything from when he lost control, he looked extremely panicked and kept apologizing again and again.
Hiru wasn't particularly bothered about being attacked. What puzzled him was why Tanjiro had targeted him instead of Akaza.
"Um… I think I entered the state Teacher mentioned—the Transparent World," Tanjiro said while trailing behind him. "I could tell that Akaza was different from humans… but Mr. Hiru, you…"
Hiru raised a hand and covered his face, completely unprepared for that explanation.
"…Ah. Right. If that's the case, I guess I really do look less human."
Silence settled between them for a moment.
Still, catching the familiar scent coming from him, Tanjiro couldn't help trying to comfort him.
"Mr. Hiru, please don't feel too discouraged. Actually, you're more human-like than Akaza. It's just that my mind wasn't clear at the time, so I treated you like an enemy. After all, having that many hearts and brains inside your body is really—"
"Shut up. Immediately."
"…Yes. I'm truly, deeply sorry."
By the time they finally arrived at Tamayo's residence, Hiru had already managed to give her the emotional equivalent of a heart attack.
She had known him and Yoriichi since the Sengoku era.
Back then, she had witnessed the two brothers frighten Muzan into blowing apart his own body just to escape. Later, she also witnessed two equally shocking events—Hiru overcoming the sun, and Yoriichi voluntarily becoming a demon.
After that, the brothers withdrew from the world and lived in seclusion.
Tamayo continued saving lives and atoning for her sins while quietly monitoring Muzan's movements. Only in recent years, when his actions grew increasingly brazen, did she reach out to them again.
The two emerged from hiding and resumed investigating Muzan.
Yet somehow, in less than a week after returning, the pair of demons had joined the Demon Slayer Corps—and even become Hashira one after the other.
Tamayo herself had been dragged into the open as well.
Still, they had indeed been successfully eliminating Muzan's followers, which at least brought her some measure of comfort.
But no matter how she thought about it, she had never imagined that Hiru would bring her yet another demon who had conquered the sun.
Another one.
With that thought, Tamayo looked at Tanjiro, who wore an awkwardly innocent expression. In the end, she couldn't bring herself to scold him and only sighed.
"I understand. I will prepare the medicine again, Yushiro, draw Tanjiro's blood and begin the analysis."
"Yes, Lady Tamayo!"
Watching Yushiro approach with a fierce expression and a syringe in hand, Hiru let out a quiet sigh.
"…Well, sorry for the trouble. I didn't expect Tanjiro's talent as a demon to be this high. He overcame his bloodlust incredibly fast, and now something like this happens…"
But Tamayo's face showed deep concern.
"Even though he has broken free from Muzan's control, he is still ultimately one of Muzan's demons. Muzan must already know about this and now your identity has been exposed within the Demon Slayer Corps. With everything in turmoil like this…"
"I'll deal with the Demon Slayer Corps side as soon as possible," Hiru said, lowering his gaze. "The only issue now is accelerating the medicine. How long will the new formula take?"
"I understand," Tamayo replied. "However, several ingredients must be imported from overseas. Even if we ask Mr. Shinjuro to use his connections, it will take at least a month to obtain them.
"Adding the time needed to prepare the medicine, forty days is the absolute fastest I can promise."
"Ask Ubuyashiki to help directly," he said. "In any case, the sooner the better—hmm?"
Halfway through speaking, he suddenly looked upward.
A smile slowly spread across his face.
"Finally here. I was wondering why my brother was taking so long this time."
"Huh? Teacher is here?" Tanjiro asked.
"Mm. Perfect timing."
Hiru watched as Yushiro set down the syringe and hurried out of the basement.
"I still have something I want to discuss before the Hashira Meeting."