Rubbing his eyes, Si Shu realized it was already daytime.
"Was I asleep just now?"
Recalling the events from before, he realized that he must have unconsciously learned Total Concentration Breathing. Yoriichi's booklet had mentioned it specifically: those who mastered Total Concentration would subconsciously maintain the breathing technique, even in their sleep.
He definitely felt different than before. Although he had only just learned Sun Breathing, his body had undergone a world-shaking transformation. He was brimming with energy, feeling as if he possessed limitless strength. His muscles were firmer, his gaze was sharper, and his breathing was smoother and more effortless than ever.
Si Shu had taken another solid step toward becoming the world's strongest.
He walked to the training ground and began his daily exercises: swinging his sword, hitting the sandbag, running, pushing a giant boulder...
After several hours, Si Shu had gone through the entire regimen. He clenched his fists simply and shook his head with a hint of disappointment. With the improvement of his strength, these exercises could no longer provide him with any higher-level benefits. After training for so long, he felt not the slightest bit of fatigue.
Just as he was wondering what training methods he should adopt next, a scattered crowd in the distance caught his attention. Following the flow of people, Si Shu saw that they were all converging on a public square.
"That place... I think that's the...?"
Carrying this question in his mind, Si Shu stopped a girl who was walking toward the square. She looked to be around ten years old, with faint freckles on her face and two pigtails on either side of her head. Her eyes were still a bit hazy, as if she had just woken up and wasn't fully alert.
"Excuse me, miss," Si Shu said with a charming smile. "I was wondering why everyone is gathering over at that square."
The girl, who was already in a grumpy, just-woke-up mood, was about to snap at the person who had stopped her. But when she turned around and saw Si Shu's smile, her attitude changed completely. He was handsome and polite, and he instantly captured her attention. All her anger was tossed out the window.
Unlike his master, Si Shu was not a cold or distant person. In just a few sentences, he got all the information he wanted from the girl, whose name was Hanaori.
It was just as he had suspected: the square was a designated area for lectures on Breathing Styles. Usually, they were taught by swordsmen who had been practicing for a few years. But today, the square was welcoming a Hashira of the Demon Slayer Corps.
The current Flame Hashira, Rengoku Toujurou.
It was precisely because of the Flame Hashira's arrival that children like Hanaori, who hadn't yet reached the required age, had a chance to learn about Breathing Styles ahead of time. Normally, one had to be at least twelve years old to even be considered for such training.
"A lecture from the Flame Hashira himself? Sounds interesting," Si Shu thought. "It wouldn't hurt to hear another person's perspective on Breathing Styles."
Following the crowd, Si Shu walked into the square. He found an inconspicuous spot to sit down and began to observe his surroundings.
In the center of the square stood a young man in his twenties. He had long, yellow-and-red-tipped hair and sharp eyebrows above a pair of bright, energetic eyes. The slight upward turn of his lips suggested he was a passionate and fiery individual.
This was the current Flame Hashira, Rengoku Toujurou.
After a brief observation, Si Shu couldn't help but marvel at the strength of the Rengoku family's genes. Whether it was Toujurou, or the Rengokus from hundreds of years later like Shinjurou and Kyoujurou—or even the one with no talent for swordsmanship, Senjurou—you couldn't say the family resemblance was faint; you could only say they were absolutely identical.
Seeing that the square was mostly full, Toujurou cleared his throat and shouted loudly.
"My friends! Thank you all for coming to my lecture on Breathing Styles today! Without further ado, let's begin! First, I would like to ask everyone: what exactly is the principle behind Breathing Styles?"
At the Flame Hashira's question, everyone in the audience, without exception, began to think seriously. This was a chance to impress a Hashira, an opportunity that might not even come once a year. Before long, people started offering their answers.
"Is it to obtain some kind of unseen energy from the air?" "Don't be ridiculous! It's definitely to stimulate the energy inside our bodies! It's our inner cosmos!" "I... I... I got nervous and forgot!"
Toujurou waved his hand to calm the nervous corps member and shook his head with a smile.
"I'm afraid to say that none of your answers have my complete approval. Even for those of you who have received instruction before, your answers are only vague concepts. But I believe that in your future training, you will all come to understand it!"
After saying this, Toujurou let out a hearty laugh.
Watching Rengoku Toujurou laugh by himself in the middle of the square, Si Shu couldn't help but complain internally. Are all the teachers in the Rengoku family like this?
Wanting to get to the main topic, Si Shu felt he had to speak up to break the deadlock.
"The principle of a Breathing Style," he said, his voice clear and steady, "is to expand the lungs as much as possible. This allows the blood to obtain a large amount of oxygen in a short period of time."
As soon as he spoke, he instantly drew the attention of the entire audience.
"Holy crap, that sounds so scientific!" "Where did this guy come from? He's handsome, well-spoken, and so young!" "You don't know him? I recognized him the moment I saw him. That's my future husband!"
Ignoring the last girl's comment, Toujurou gestured for the crowd to be quiet. Si Shu's explanation had astonished him; even Toujurou himself couldn't find a single flaw in it.
"Ahem. His explanation is excellent! Everyone, please take a moment to think about it!"
A minute passed quickly, and Toujurou continued his lecture.
"Now that everyone should understand the principle, I will explain the specific methods."
At this, everyone in the square, including Si Shu, perked up and listened with rapt attention.
"Based on my personal experience, the specific steps are as follows. First..."
In just a few minutes, Rengoku Toujurou generously shared all the experience he had accumulated on Breathing Styles without reservation. He even included some of his personal tricks, saving the listeners from a lot of unnecessary detours and mistakes.
"Everyone can now try to feel it out for yourselves, based on what I just said. Try to use the breathing technique on your own," Toujurou said, crossing his arms. "If anyone has any questions, you can ask me now!"
It had to be said, the Rengoku men might have a tendency to be a bit self-indulgent, but when it came to teaching, they were all passionate and incredibly patient. Toujurou carefully answered every question that was asked.
Before long, everyone had closed their eyes and was attempting to use the breathing technique. Toujurou nodded, his face filled with satisfaction. Although they were still weak now, just beginning to touch the world of Breathing Styles, he believed that in the future, they could become the pillars supporting the Demon Slayer Corps.
As he observed the crowd's expressions, one child suddenly caught his attention. His outstanding looks were enough to make him a focal point, but what concerned Toujurou more was his breathing. Unlike everyone else, the boy's breathing was steady and powerful. It was rhythmic, distinct, and remarkably skilled.
It was hard to imagine that this level of control would appear in a child who couldn't be more than eight years old. Toujurou had to admit, even he hadn't been at this level when he first started.
Just as Toujurou was marveling at this, coughing sounds began to break out across the square. Soon, the others began to open their eyes, having lost their rhythm or run out of breath. To maintain a Breathing Style for a long time required not only talent, but more importantly, long-term training.
Before long, the only person in the square who still had their eyes closed was Si Shu.
Breathe in... breathe out... breathe in... breathe out...
At that moment, Si Shu was completely immersed in the world of breathing, entirely unaware of what was happening around him.
[Host detected practicing Breathing Style. Proficiency increasing...] [9020... 9040... 9060...]
As time passed, Si Shu's understanding of the breathing technique deepened. By maintaining the technique for so long, he naturally became the center of everyone's attention. Everyone, from the first-timers to the preparatory members who had been training for years, was staring at him with the same expression one would use to look at a monster.
In that moment, their thoughts were surprisingly unified.
"Is this guy... really human?"