Chapter 17: Senior, How Do You Do It?
Several days passed.
At Mt. Sagiri, Natsuya had become quite familiar with the three Water Breathing swordsmen.
Although his instructor, Urokodaki Sakonji, always wore that intimidating Tengu mask, he was actually a meticulous and kind-hearted old man. After agreeing to teach Natsuya, he didn't hold anything back.
The very next day, he took Natsuya up the mountain to begin a joint training program with the two children.
Furthermore, perhaps worried that Natsuya wasn't used to the living conditions, Urokodaki even went down the mountain that same night to buy him a new set of futons from the town.
As for the two kids, Sabito and Giyu...
In Natsuya's eyes, they were rare geniuses.
According to Urokodaki, Sabito hadn't been training for very long, and Giyu for even less time. Yet, both had already completed their basic physical conditioning and mastered the Water Breathing forms.
Sabito was significantly stronger than Giyu. Urokodaki mentioned that he planned to start Sabito on Total Concentration Breathing training soon.
From Natsuya's perspective, Sabito was already strong enough to pass the Final Selection. Compared to the other candidates Natsuya had seen at Lake Ashi, Sabito's stats and skill levels were far superior.
His personality was steady, and his swordsmanship was incredibly efficient. His forms were standard but flowed seamlessly, with an aggressive rhythm that gave his Water Breathing a turbulent, crashing quality. He was an offensive swordsman who didn't rely on tricks but had zero major openings.
He's strong.
Compared to him, Seiko—who also used Water Breathing—was basically a "Water Breathing Mob Character A" background asset.
Giyu, on the other hand, was much more introverted and quiet.
He usually wore a stoic expression, his face as still as a stagnant pool. It honestly made Natsuya wonder if he was a lost child from the Uchiha clan.
Only when Sabito was around would Giyu occasionally crack a smile.
However, after a few of Natsuya's dinners, Giyu had warmed up slightly to this sudden "Senior Brother."
As for strength, Natsuya's evaluation of Giyu was complex.
Because he was younger, his stats were naturally lower than Sabito's. That was normal.
But in terms of comprehension and talent, Giyu seemed to have a higher ceiling. whenever Urokodaki demonstrated a technique, Giyu's [Skill Proficiency Bar] filled up nearly 50% faster than Sabito's.
The issue was stability. His progress bar would often freeze completely. Natsuya couldn't tell if the kid was spacing out or if it was due to the "lack of confidence" Sabito had mentioned.
Fortunately, Sabito was there. His constant encouragement and private sparring sessions ensured that even if Giyu's progress stalled, he never truly fell behind.
Giyu's swordsmanship mirrored his personality: passive, yet colder and more condensed. He looked calm, always observing and waiting. Only at the last possible second would he rely on his terrifying intuition and reflexes to strike with the perfect counter.
A defensive counter-attacker...
"Senior! Senior! SENIOR!"
Sabito's shouting broke Natsuya out of his "AFK Mode."
Watching the training animation return to normal speed, Natsuya turned his head to look at the concerned Sabito.
"What's up?"
Sabito handed him a bento box prepared by Urokodaki. "It's already noon, Senior. You've been swinging your sword for four and a half hours straight."
"Ah? Is there a problem?"
"Master said that training too hard without rest is counterproductive. Not only does the efficiency drop, but it also damages the body."
Sabito looked at the bento in his hand. "Besides... if I didn't stop you, I feel like you would have kept going until nightfall."
Natsuya dropped his breathing rhythm. Steam rose from his body, distorting the air around him.
It was the honest shape of power and effort. Unadorned, silent proof of how far a human body could be pushed.
Picking up a towel to wipe his sweat, Natsuya pondered.
There's a mechanic like that?
I thought if I maxed out the training duration and let the System auto-grind, I'd get the most XP.
So I actually need to manage my stamina bar for optimal gains?
While Natsuya was thinking, Sabito and Giyu exchanged a look. Both saw admiration in the other's eyes.
High-intensity training all morning was already a test of stamina and self-discipline. But to maintain perfect form and total concentration for that long, like Natsuya did, was unheard of.
And he did it every single day.
Not only that, but whether it was Urokodaki's training regimen or daily chores like cooking, fetching water, chopping wood, or fishing... Natsuya approached everything with that same terrifying, absolute focus.
What incredible grit and willpower.
Across from them, Natsuya was drying off. Sweat ran down his sharp jawline like a stream. Under the sunlight, his heaving muscles looked like they were coated in a breathing glaze.
His back muscles expanded and contracted like wings. His abs were as tight as tempered iron plates.
No wonder Master Urokodaki had been praising him non-stop for the last two days.
"This is the manifestation of merging life and training to the extreme. This child might truly be a monstrous talent."
Thinking back to how he had felt a twinge of jealousy over his Master's attention to Natsuya, Giyu felt a wave of shame.
He deserves the Master's attention. He deserves to be strong.
"Giyu, one day we'll be as strong as Senior," Sabito said, flashing a serious smile as if reading the undercurrent of Giyu's emotions.
"We're going to be Demon Slayers. Having a swordsman like Kokonoe-senior on our side should be inspiring."
"We shouldn't feel inferior because he is strong. We should strive to become like him."
He patted Giyu on the shoulder.
Natsuya put on his shirt and saw the two kids whispering. He naturally tilted his chin up. "Oi~ don't just stand there. Eat your lunch and rest. I want to practice forms with you two this afternoon."
Senior is thinking about getting stronger every single second, the two boys thought in unison.
"Hey, Senior... how do you maintain that focus?" Sabito asked curiously. "Even I can't push myself to such a harsh degree."
Effort?
Isn't it just pressing a button?
Set the training plan, then wait for the System to auto-play.
Then Natsuya remembered these were NPCs, not other players. The game was so realistic he often forgot.
"It's not just focus, Sabito."
"It's 'Flow State Severance'."
Sabito blinked. "...Flow State... Severance?"
"Exactly." Natsuya nodded, his eyes looking distant (mostly because he was checking a notification). "When the spirit is extremely focused and enters a 'Flow,' normal people eventually exit due to fatigue."
"But I am different."
"In that moment, I actively 'sever' my perception of fatigue."
He tapped his temple, proceeding to make things up on the spot.
"Just like using Breathing to forcibly enhance physical functions, I use a special meditation to temporarily cut 'Exhaustion,' 'Boredom,' and the 'Passage of Time' out of my consciousness."
"My body continues to move, but my Heart enters a state of... absolute nothingness."
"External time loses its meaning to me."
Sabito's mouth hung slightly open, his eyes shining with shock and realization. "So there is such a technique... so Senior isn't just 'enduring' it, but entering a higher realm of cultivation?"
"You could understand it that way," Natsuya said solemnly, nodding slightly.
Beside them, the ever-silent Tomioka Giyu almost choked on his rice.
He didn't look up, just glanced at Natsuya with those deep blue eyes. There was no emotion in his gaze, yet it said everything.
He's making that up.
Giyu lowered his head and continued eating.
He had heard Natsuya's story from Master Urokodaki.
Demons took everything from him. His family, his sister.
This Senior was just like them—burned and driven by the flames of hatred every night.
Driven to become strong enough to slaughter every demon in existence.
It wasn't some "Flow State Severance."
It was the hatred of revenge.
Under that expression that seemed to wander off into space, lay a paranoia and obsession perhaps even stronger than his or Sabito's.
Thinking of the image of his own sister dying to protect him, Giyu's eyes and breathing shifted slightly.
He felt like he understood this Senior a little better.
Perhaps training wasn't about "persisting."
It was that not training meant "stopping."
And for a swordsman starving for revenge, stopping meant Death.
If I don't fight, I die.
That must be what Kokonoe-senior feels.
Sabito fell into deep thought, digesting Natsuya's "theory." Giyu ate his rice, his heart equally turbulent.
Natsuya turned around expressionlessly and opened his bento.
Rice balls made by Urokodaki, and a few pieces of fried meat.
The corner of his mouth twitched slightly.
I think I bluffed my way through that one.
But honestly, that theory kind of makes sense for the game mechanics, right?
As expected of me.