Master Blacksmith in Demon Slayer

That was completely reckless behavior, blood rushing to his head without a single thought about whether he might scare the girl...

"Impetuous, so damn impetuous!"

He muttered under his breath as he followed behind Kochou Kanae.

"What?"

Kanae's light, questioning voice came back.

Tetsu no Sosuke shook his head. "Nothing. Let's go home."

Chapter 29: Correspondence

The Butterfly Estate was lively today, with Hidden members bustling back and forth, hauling in quite a bit of stuff.

In a corner of the backyard, a shed had been set up.

The furnace was already built, and the anvil had been brought over.

Though he was set on becoming a member of the Demon Slayer Corps, Tetsu no Sosuke clearly couldn't just abandon his identity as a swordsmith. Whether it was Ubuyashiki Kagaya's intentions or his own need to boost his strength, forging Nichirin Blades was essential.

So the sword-forging shed had to stay.

But considering that the Butterfly Estate occasionally took in injured patients, and worried about disturbing their recovery, Tetsu no Sosuke's forge was placed in a deeper, quieter spot.

Right now, he sat off to the side, watching the Hidden members work, while reading a letter.

The letter was from Kawahara Chintetsu. The gist was to remind Tetsu no Sosuke not to forget his identity and duty as a swordsmith—even if he learned sword techniques and eventually became a Demon Slayer Corps member, he must never neglect the heavy responsibility of forging Nichirin Blades.

It also asked about the Nichirin Blade he'd made for Kochou Kanae.

What special technique had he used to give the blade the power to suppress demons?

He'd thought Ubuyashiki Kagaya would be the one to ask, but instead, the inquiry came from Kawahara Chintetsu.

He'd originally planned to visit the Swordsmith Village to explain things before formally starting his sword training.

But the letter told Tetsu no Sosuke not to bother coming back. During his training period, and even after becoming a Demon Slayer Corps member, he was no longer allowed to wear the Fireman Mask.

This information suddenly gave Tetsu no Sosuke a strange feeling.

"It's like... they're not just making me a Demon Slayer Corps member for the sake of it..."

He couldn't quite untangle the implications for now, so he stopped mulling it over and turned his mind to how he should reply to Kawahara Chintetsu.

He went inside, picked up paper and brush, and let the tip move. First came the proper greetings, then some promises about not forgetting his responsibilities. After a moment's hesitation, he wrote: "Regarding the forging of the Nichirin Blade, it stems from a forging method I stumbled upon by chance. This method fuses Breathing Techniques with forging skills. The Village Chief should recall that before this, I had an accident on the mountain—that's when I obtained this legacy. The original text was destroyed by a mechanism, so I've excerpted a portion and included it as an attachment. Please, Village Chief, carefully select young swordsmiths in the village to try it, and see if they can forge Nichirin Blades that suppress demons, just as I did."

Writing this, Tetsu no Sosuke paused, then continued: "As for practicing the Breathing Technique, please don't push it. If any accident occurs, stop immediately and seek help from an experienced swordsman. If there are any questions you need me to answer, Village Chief, feel free to write, or I can return to the village to clarify."

With that, he let out a small breath, copied a small portion of the Breath of the Sun onto another sheet of paper, and clearly labeled it with the name "Gale Sun Hammer."

He'd thought this through carefully.

There was no way to completely hide the Breathing Technique. Shinobu Kocho and Kochou Kanae had both seen it with their own eyes—no ordinary swordsman's physique could swing a hammer at that speed in such a moment.

So, pinning it on that mountain accident and explaining it that way also answered the question of how a swordsmith could display such ability.

Second, by sharing a part of the Breathing Technique, he could let them try to mass-produce Nichirin Blades that suppressed demon regeneration for the Demon Slayer Corps.

If it succeeded, the Corps' combat power would skyrocket—something Tetsu no Sosuke very much wanted to see!

If it failed, this small portion could still help the village's swordsmiths enhance their physical capabilities.

Of course, all of this depended on them being able to successfully use it.

But just thinking about it, his brow twitched. "Then again, who knows if they'll even be willing to try. The swordsmiths in the village are fiercely devoted to their craft. Hmm, maybe not—maybe they'd be willing to experiment for the sake of forging better Nichirin Blades?"

He folded the letter and slipped it into an envelope.

Leaning back slightly to ease his back, his mind drifted to another matter.

In a thousand years, had no one ever tried to fuse Breathing Techniques into forging?

Probably not.

But the Breath of the Sun had long been lost, and the various derivative breaths might not have the same effect on Nichirin Blades.

"If someone had succeeded, at least some corresponding traits should have emerged."

He frowned, suddenly feeling like the odds of success were slim.

"Could it be that the Sunblaze attribute's birth relied not just on the Breath of the Sun, but more importantly on my cheat's correction?"

That was something that still needed verification.

As for not sharing the full Breath of the Sun, partly it was to get feedback from the first attempt, and partly... it was a bit of selfishness on Tetsu no Sosuke's part.

"Anyway, what I've given them should be enough to trigger the Gale Sun. If it fails, then this ends here."

Pushing aside his thoughts, Tetsu no Sosuke handed the letter to Kochou Kanae, asking her to send it through the channels to the Swordsmith Village.

He wanted to spend more time with her, but considering the Hidden's work, he went back to his own courtyard first. Seize the moment, yes, but the long game mattered more.

No sooner had he stepped into his yard, though, than he found an uninvited guest.

The man lay on a tree branch, tilting his head to look down. Bandages wrapped around his face, but his two eyes were completely different colors—the right one gold, the left one green. His medium-length hair drifted loosely, and on his shoulder, a small white snake flicked its tongue at Tetsu no Sosuke.

Serpent Pillar—Iguro Obanai!

Tetsu no Sosuke was momentarily stunned, but then saw him flip over and land.

"I'd like you to forge a Nichirin Blade for me."

Iguro Obanai got straight to the point, then asked, "You're Tetsu no Sosuke, right?"

"..."

Tetsu no Sosuke was speechless for a moment. Not even confirming his identity before saying something like that—was that really okay?

So he had to ask, "I can do it, but may I ask who you are?"

Author's note:

This chapter... I'll release it as early as possible today~ So today's update time is earlier.