After completing the final draft of his Talent Selection and Development Program, Tachibana Kyūjō remained at the Demon Slayer Corps' headquarters for one more week.

During that time, he didn't just refine his proposal through long discussions with Ubuyashiki Kagaya—he also spent time meeting various Hashira, both the long-serving veterans and the newly appointed ones.

Among them was Himejima Gyōmei, who had just ascended to the title of Stone Hashira.

And of course, there was Rengoku Shinjurō—the current Flame Hashira, and the man who would one day become the father of the next generation.

Just like his son in the future, Shinjurō had a blazing spirit. His laughter was loud, his smile wide, and every word he spoke seemed to burn with passion.

Kyūjō got along quite well with that kind of personality.

In fact, thanks to Shinjurō's energetic invitation, he ended up visiting the Rengoku household.

There, he sparred at the family dojo—a match that ended with the young Kyojurō, just a few years younger than Kyūjō, awkwardly calling him "Uncle Kyūjō."

One afternoon, after a particularly intense session with Shinjurō, Kyūjō suddenly stopped walking and grew serious.

"There's something I need to tell you," he said, looking straight at Shinjurō.

The Flame Hashira raised an eyebrow. "What is it?"

"While we were sparring… I loosened my sensory control on purpose. I picked up something strange from your wife's aura."

"Something… concerning."

Shinjurō looked unconvinced. "That can't be right. Ruka's always been healthy. In all our years of marriage, she's never been seriously ill."

But Kyūjō held his gaze firmly.

"I hope I'm wrong too."

"But this power of mine… it's never lied to me before."

He took a deep breath, activating Flame Breathing. A thin but piercing wave of heat radiated from his body—though it wasn't visible, the warmth that filled the air was unmistakable.

It wasn't just fire. It was as if his breath, his heartbeat, his very soul had become one with the flame.

Shinjurō's eyes widened.

"...You…"

"You've mastered Flame Breathing?!"

"And not just that… your level of mastery is…"

Kyūjō calmly ended the technique, letting the heat dissipate as he returned to his usual Thunder Breathing stance.

"This isn't just a sword technique," he said quietly. "It's a state of perception… a realm within the world of the blade."

"Some call it… the Transparent World."

"If you have the time, look through your family's oldest records. There might be mentions of it."

"With this, I can see—or rather, sense—the structure of a human body. Every imbalance. Every flaw."

"And from what I observed… Ruka's condition is not good."

"The life energy flowing from her is faint. I believe there's an abnormality in her heart valve."

"And judging from the fluctuations in her aura… this didn't happen recently. She's been hiding it for a long time."

Shinjurō was speechless.

His mind went blank. Without saying a word, he spun on his heels and sprinted toward the house. Kyūjō followed behind him at a steady pace.

— — —

Inside the bedroom, Ruka was peacefully sewing clothes for her children.

Her smile was gentle. Her presence calm.

But the moment the door burst open and Shinjurō stormed in, eyes filled with fear, she looked up in surprise.

"What's wrong? What happened to you two?"

Shinjurō stared at her, chest heaving. "Ruka… have you been feeling unwell lately?"

She paused for a moment, then slowly lowered her hand to her chest.

"There's been a bit of discomfort… but it's just an old illness. Nothing serious."

"I didn't want to burden you with something so small."

Those words struck Shinjurō like a blade through the heart.

He turned to Kyūjō, who stood still, silently observing her with intense focus.

"The structure of her heart valve… it's not like that of a normal human," Kyūjō finally said, voice calm but heavy.

"It may be congenital."

"Unfortunately… even though I can sense it, I'm no doctor. I don't know how to treat it."

He looked at both husband and wife, speaking frankly:

"Her condition is serious. You need to prepare yourselves mentally."

"Find a doctor. Immediately."

— — —

The next morning, Shinjurō summoned the best doctor in the region.

But as expected, the results were grim.

"There is no cure," the doctor said gently. "There's no known treatment."

Shinjurō returned to Kyūjō with a devastated expression, his steps unsteady.

"...Kyūjō. There has to be a way, right?"

"There has to be something you can do…"

His eyes were filled with one last, desperate hope.

Kyūjō fell silent.

In this world—a world overrun by demons—there weren't many who could treat a condition like this.

But one name did come to mind.

Muzan Kibutsuji.

The first demon. The oldest. A creature who had lived for over a thousand years.

In his obsession with overcoming his weakness to sunlight, he had explored the limits of biology, toxins, and medicine far beyond any human's reach.

Even if Muzan lacked talent, a thousand years of relentless study had surely taught him more than enough.

But of course, asking Muzan was out of the question.

He would never save a human unless he had something far more sinister in mind.

Still… there was one other possibility.

A former human. A true doctor.

A demon who lived quietly, in secret… in Asakusa, Tokyo.

Tamayo.

Before Muzan turned her into a demon, Tamayo had been a skilled physician.

Even after her transformation, she chose to walk the path of healing. For centuries, she dedicated her life to helping others—and to searching for a cure to the demon curse.

If anyone could help… it was her.

But there was one problem.

Tamayo was still a demon.

And Shinjurō, a proud Flame Hashira, might not accept help from the very kind he was sworn to destroy.

Kyūjō weighed his options carefully… then finally spoke with measured caution:

"I've heard there's a foreign-run hospital in Asakusa, Tokyo."

"They've brought advanced technology and medical knowledge from overseas."

"Maybe… you could try there first. It's worth a shot."

If the hospital failed—

Then Kyūjō would find Tamayo himself.

— — —

That very evening, Shinjurō sent a formal request to Oyakata-sama.

Once the permission came through, he gathered his entire family and set off for Tokyo.

Naturally, Kyūjō went with them.

He knew—if he didn't go, who else would find Tamayo?

His quiet concern for the Rengoku family didn't go unnoticed.

Even the two young boys, Kyojurō and Senjurō, had started calling him "Uncle Kyūjō" without hesitation.

— — —

Two days later, they arrived in Asakusa.

Kyūjō accompanied the family to the foreign hospital that, to his relief, did actually exist.

At least… they had a real place to start.

In a quiet corner near the hospital courtyard, Kyūjō pulled Shinjurō aside and spoke in a low voice:

"Shinjurō, stay here for now. Let your family rest. I know a few names in Tokyo—doctors worth checking out."

"I'll go see what I can find."

"If there's anything… I'll come back tonight."

Shinjurō gave a silent nod.

And with that, Kyūjō turned and walked away—heading toward the woman who might be their final hope.

Tamayo.

— — —

✨ Special thanks to my newest Patreon supporters!

Your support keeps this series alive and growing!

— — — — — — — — — — — — — — — —

Joseph Sepulveda, Big Brizzz, Michael Thomas, Austin, Just Some Guy With A Mustage, Kloud Paradizo, Hamza Ahmed, King, Haznyb, Michael White

— — — — — — — — — — — — — — — —

📚 Want to read more chapters or get early access?

Join my Patreon here:

🔗 patreon.com/FaaanzKun

✅ Enjoy 30+ chapters ahead of WebNovel

✅ Get 2 new chapters every day exclusively on Patreon

Already caught up with the latest chapter on WebNovel?

Continue the journey early for just:

$5/month

Join now and dive deeper into the story—weeks ahead of public release!

Thank you for your amazing support 💖

— — —