The next afternoon, on the mountaintop platform.
Teiichi and his teacher, Shoma, sat cross-legged facing each other.
"To learn Wind Breathing, you first need to understand what Wind Breathing is."
"You can break Wind Breathing down into two parts: wind and breathing."
"Wind is formless, swift, free, and flexible, among other things. You need to understand what wind is. You've already spent several weeks training in this, so I won't say any more about it."
"Today, we'll focus on breathing!"
"Breathing, or a Breathing Style, is a specialized breathing technique. It strengthens the heart and lungs, allowing the body to take in large amounts of oxygen in a short time. This greatly enhances physical capabilities, temporarily giving humans physical abilities on par with demons."
"Watch closely. I'll demonstrate it for you. This is Wind Breathing."
"Hiss~~ hiss~ whoosh~~~"
"..."
Seemingly deliberately, as Shoma demonstrated Wind Breathing, although Teiichi could not see the airflow produced by his breathing, he could clearly hear the pattern of his teacher's inhalations and exhalations.
A moment later, Shoma stopped the breathing exercise and looked at Teiichi.
"That's Wind Breathing."
Teiichi nodded, impressed despite not understanding.
"How much did you remember?"
"Ah... I was supposed to memorize that?"
An exasperated voice rang out across the mountaintop.
"Of course you were!!! Why would I demonstrate it if you weren't supposed to memorize it? How will you breathe when you use Wind Breathing later if you don't remember it?"
"Watch. I'll demonstrate it twice more. You'd better remember it this time."
Knowing he had made a mistake, Teiichi nodded repeatedly and focused his attention on Shoma.
Shoma took a deep breath, then slowly exhaled, as though becoming one with Wind Breathing. His movements were fluid and natural, each breath carrying strength.
A short while later, the two breathing demonstrations were over.
"You remembered it this time, right?"
"Yes, I remembered."
"Good. Now come here, put your hands over my lungs, close your eyes, and pay close attention to what happens inside the body when using a Breathing Style."
At his words, Teiichi stepped forward, placed his hands on Shoma's upper chest, and closed his eyes, concentrating fully on what he could sense.
At first, there was only darkness before his eyes.
But accompanied by the clearly audible breathing beside his ears, the outline of a pair of lungs actually began to emerge in his mind like a phantom!
The lungs seemed alive, pulsing rhythmically, every contraction and expansion filled with power. Deeply captivated by this wondrous image, Teiichi could not help losing himself in it.
"All right, how did that feel?"
After a long while, Shoma's voice brought Teiichi back to his senses.
Teiichi opened his eyes and glanced at Shoma, then lowered his head, recalled what he had just felt, and nodded.
"Yes, I think I've more or less got it."
"Good. Now try Wind Breathing the way I just taught you. Let me see how well you've learned it."
At his words, Teiichi recalled Shoma's demonstration, trying to imitate his movements and breathing rhythm.
"Hiss~~ hiss~ whoosh~~"
As Teiichi began to breathe, Shoma's eyes beside him grew wider and wider.
This kid actually learned it just like that!
I only explained it a little!
Hmm, he's about to come around. No, I can't let him get too proud. I need to take him down a peg. I'll just tell him his talent is average.
"Cough, cough..."
A little later, after completing several cycles of the Breathing Style, Teiichi finally could not hold on any longer and began coughing.
Once Teiichi's coughing had eased a little, Kazeno Shoma spoke.
"It seems your memory isn't too bad, and your compatibility with Wind Breathing has reached the normal level for an average person."
Hearing Shoma's words, Teiichi nodded. Although he was a transmigrator, what use was a transmigrator without a system? Recalling his body's reaction when he first used Wind Breathing, Teiichi asked a question.
"Teacher, why did my body tremble slightly from time to time while I was breathing just now?"
"When you were breathing just now, although there was nothing wrong with your overall rhythm, there were still flaws in some of the details. Those flaws caused your body to tremble slightly. Try again. This time, I'll point out the problems while you breathe, and you can adjust accordingly."
Teiichi nodded and began breathing again.
"That breath was too short. Make it a little longer."
"A little longer."
"That one was too long. Shorter."
"Yes, the overall rhythm is fine now. You spent all that time feeling the wind on the mountaintop before, didn't you? Now concentrate, feel the power of the wind, and let it flow through your body."
A long while passed.
"Huff~ huff~"
"Teacher, I can't keep going. I'm so tired. Why is even breathing this exhausting?"
"Lasting this long on your first Breathing Style training session is already pretty good. It's tied to your constitution. You're only nine, after all. How long did you expect to last?"
Hearing this, Teiichi, who had been worried that something might have gone wrong, felt reassured.
"Teacher, does that mean the amount of time I lasted was short or long?"
"Of course it was among the shortest. When you use a Breathing Style, it not only greatly enhances your constitution for a short time, but also brings an extremely slight improvement to your constitution. Though extremely slight, as it accumulates over time, the body's constitution gradually surpasses that of ordinary people. That's also why we demon slayers can fight demons."
At this point, Shoma paused before continuing.
"So, from now on, unless you're out on a demon-slaying mission, you can use your Breathing Style whenever you have nothing else to do. Try to reach Total Concentration: Constant as soon as possible."
"Total Concentration: Constant..."
"Yes, Total Concentration: Constant means using your Breathing Style twenty-four hours a day, whether you're eating or sleeping. Once you reach Total Concentration: Constant, your physical capabilities will improve every moment. Although the improvement is small, it keeps happening without stopping.
"Also, Total Concentration: Constant is the minimum requirement for becoming a Hashira. The sooner you reach Total Concentration: Constant, the greater your future achievements will be."
"All right, after all that talking, you should have caught your breath. Keep practicing your Breathing Style."
"Huh? Haven't we barely said a few words?"
"Quit complaining. If I tell you to practice, practice. Would I steer you wrong?"
"..."
A month later, the sun shone brightly, and the mountaintop platform was peaceful and tranquil.
As usual, Teiichi arrived early. He quietly walked onto the large boulder by the cliff, crossed his legs, slowly closed his eyes, and began adjusting his breathing rhythm. His chest rose and fell steadily with each inhalation and exhalation, while his mind was wholly absorbed in turning inward.
Time passed second by second, and Teiichi's breathing grew increasingly steady and deep, as though he had become one with his surroundings. Gradually, he began to feel a gentle breeze blowing from afar, brushing softly over his cheeks and hair, bringing traces of coolness. The wind did not stop, but circled around him without leaving, as though dancing with him.
At some point, Shoma silently arrived on the mountaintop platform. He stood quietly several meters away, his gaze fixed on the boy sitting cross-legged on the boulder. Feeling the hem of his clothes stirred by the wind that had come from nowhere, his eyes revealed deep approval.
Only after a long while, once Teiichi had settled his mind and evened out his breathing, did Kazeno Shoma slowly walk over to him.
"Well done. You've now gained an initial grasp of the correct breathing method. Next, it's time for you to learn some actual Wind Breathing forms."
Hearing this, Teiichi immediately brightened.
"Really?"
Kazeno Shoma nodded.
"That's right, but take a few steps back first."
Teiichi immediately did as instructed, swiftly putting some distance between himself and Shoma. Once Teiichi had steadied his stance, Kazeno Shoma reached for the Nichirin Blade hanging at his waist and drew it from its sheath.
"Wind Breathing, First Form: Dust Whirlwind Cutter!"