"The breathing technique I've mastered is Mizu no Kokyu (Water Breathing), one of the five foundational breathing styles derived from the original breathing technique."
On the open ground in front of the wooden cabin, Urokodaki Sakonji, wearing his tengu mask, held a sword in his hand. As he spoke, he gave the blade a casual swing.
It was just a simple motion, but to Riku, it felt different—like the blade was wrapped in flowing water.
Of course, it was only a feeling. There were no special effects on the sword itself, just a sense of momentum, like the gentle flow of a stream.
"Compared to the other breathing styles, Mizu no Kokyu is the gentlest and the easiest to master. Over the years, the Mizu-bashira (Water Pillar) position has never been vacant. No matter how quickly they fall, there's always someone to take their place."
Urokodaki continued, though his rather grim phrasing left Riku momentarily speechless.
Whoa, hold up. Is Mizu no Kokyu some kind of quick-and-dirty crash course? It's not some knockoff version, is it?
"There's no such thing as a stronger or weaker breathing style. The one that suits you is the best."
As if reading Riku's doubts, Urokodaki spoke up to clarify.
"What about the original breathing technique, then? If there's no stronger or weaker style, that's just talking about the derived breathing styles, right?"
Riku raised a question. The "original" breathing technique, the one that gave rise to all the others, sounded like it had to be something pretty epic.
His question left Urokodaki momentarily silent.
"The original breathing technique… it's different, naturally. It's a powerful force beyond the comprehension of modern people. Unfortunately, it's been lost because no one could pass it down."
After a pause, Urokodaki let out a sigh. Sometimes, being too extraordinary isn't always a good thing.
When someone is so exceptional that their peers—or even the next generation—can't even touch the soles of their feet, passing down their legacy becomes impossible.
"Uh…"
Hearing Urokodaki's words, Riku immediately thought of Tanjiro Kamado. No question about it—this original breathing technique was practically made for that kid. It didn't take a genius to figure it out.
A powerful force meant to fight against demons, lost to time? Yeah, that's got "main character cheat code" written all over it!
Riku had initially thought Tanjiro's super-sniffer nose was his big advantage, but since Urokodaki had a similar ability, that edge suddenly seemed less unique.
Now, this "original breathing" thing pops up—something so powerful that only its founder could use it, and even passing it down was impossible, leaving only the "knockoff" derived versions.
Man, no need to guess—this is totally for the protagonist.
The question was, could Riku learn this original breathing technique?
He couldn't help but wonder. And then there was Tanjiro himself—would he even awaken to it? Riku made a mental note to subtly probe Tanjiro about it later.
Either way, with Tanjiro's personality, if Riku wanted to learn it, that kid would definitely be willing to teach him—as long as Riku could actually pull it off.
"Let's get back to Mizu no Kokyu."
After his brief lament about the original breathing technique, Urokodaki steered the conversation back on track.
"Mizu no Kokyu is suited for those with a clear mind, calm and steady, with an inner peace like still water."
Urokodaki looked at Riku. After observing him for the past few days, he'd concluded that Riku had the potential to learn Mizu no Kokyu.
The training period before formally teaching a breathing technique was also a kind of test for the students.
Their attitude during training and their personality in daily life were all factors to consider.
Of course, failing to meet the personality requirements didn't mean immediate disqualification or losing the chance to learn a breathing technique entirely.
If one style didn't fit, there were other options. Not every style would be unsuitable.
For someone cheerful and passionate, with a heart burning like fire, Mizu no Kokyu might not work, but Hono no Kokyu (Flame Breathing) could be a perfect fit.
For someone with exceptional physical ability and a heart full of fervor, swift like lightning, Kaminari no Kokyu (Thunder Breathing) would be ideal.
For someone who despises evil and has a temperament as wild as a storm, Kaze no Kokyu (Wind Breathing) would suit them.
And for someone diligent and resolute, with a will as unyielding as stone, Iwa no Kokyu (Rock Breathing) would be the way to go.
But if none of the styles matched their personality, well, they'd be out of luck and eliminated.
Among the five foundational breathing styles, some are harder to learn than others. Comparatively, Mizu no Kokyu and Kaze no Kokyu are the most accessible for ordinary people, with less demanding requirements.
To learn Hono no Kokyu, you'd need not only a fiery, sincere heart but also the approval of the Rengoku family, as they've passed down Hono no Kokyu for generations.
As for Kaminari no Kokyu, the training process is tough, and the physical demands alone would weed out most people.
Iwa no Kokyu? That's the hardest of the five foundational styles to master.
Compared to explosive physical prowess, finding someone with the diligence and rock-solid willpower required for Iwa no Kokyu is even rarer.
"I see."
Riku nodded. No wonder Mizu no Kokyu was said to be the easiest to learn.
Compared to Kaze no Kokyu, which suited those with stormy, impulsive personalities, people with clear minds and calm demeanors were naturally better suited to dive into the practice.
"Honestly, with your personality, besides Mizu no Kokyu, you'd also be a good fit for Iwa no Kokyu. But I can't teach you that one."
Urokodaki was straightforward. If he had to say, Riku's personality was actually best suited for Iwa no Kokyu.
His diligence was undeniable. Even though his body didn't tire, not many could train day and night without pause like Riku did.
And his willpower? As a demon who refused to eat humans and instead sustained himself with his own flesh and blood—that went beyond mere resolve.
"No, I'll stick with learning Mizu no Kokyu from you."
Riku shook his head. After Urokodaki's explanation, he realized that Mizu no Kokyu and Iwa no Kokyu were indeed the best fits for him.
If he had to stretch it, maybe Kaminari no Kokyu could work too—his physical ability was definitely up to par, and he could get pretty passionate when he let his rationality slip.
As for Kaze no Kokyu or Hono no Kokyu? He didn't think he was the type to hold grudges against evil or have a heart burning with sincerity.
But here's the kicker: the biggest issue was that Urokodaki only specialized in Mizu no Kokyu.
If Riku wanted to learn another style, he'd have to find another trainer.
For other kids, that might just mean "switching schools" and training under a different cultivator.
But for Riku? That was a nightmare waiting to happen. Not every cultivator had a nose like Urokodaki's.
How was a demon as conspicuous as him supposed to gain the trust of retired Demon Slayers—people who'd spent their lives killing demons or retired due to injuries sustained fighting them?
Rely on Urokodaki's introduction? Yeah, that sounded way too risky.
Better to stay put and learn Mizu no Kokyu—plus, he could keep an eye on whether Tanjiro would awaken that original breathing technique.
"Alright."
Urokodaki wasn't surprised by Riku's decision.
This was exactly why he thought Riku was suited for Mizu no Kokyu. When faced with a problem, this kid could stay calm and think things through.
(End of Chapter)