Ryusei lingered at a distance first, his senses brushing over the pair.
A few hours passed, and it became clear there would be no legendary display today.
Duy and his son only ran their usual drills along the riverbank, splashing water as they went.
Guy was still just a boy in the Academy, maybe ten this year, too young to force the deeper gates open.
So, it was probably rare that they trained or demonstrated that. Probably not on many days.
Duy, though still technically a genin, carried the hidden weight of a man who could reach Kage-level heights when his body burned thanks to advanced gates.
Ryusei adjusted his expression into that narrow-eyed, polite smile that passed for gentle.
He waited until they circled back up the river, then timed his steps so he seemed to arrive from the opposite path, as if by coincidence.
"Oh—pardon me," he said, bowing his head slightly as he stepped aside.
Duy blinked, sweat dripping from his chin. "No harm done, young man! You've got a fine aura of training about you. Out here to sharpen the body as well?"
Ryusei gave a respectful nod, even though by rank he had no need.
"Yes. I've been pushing myself back in the forest, but seeing your discipline inadvertently… It's inspiring. You've been at it for hours without pause."
Duy's chest puffed slightly, though he kept a humble tone. "Training is life! A flame burns brightest when stoked every day. Isn't that right, Guy?"
Guy stopped mid-drill, panting, fists clenched tight. "Yes, Father! We'll run until even the river feels tired of seeing us!"
Ryusei let out a light laugh, not mocking but warm.
He remembered enough, Duy's unshakable optimism, Guy's earnest energy, their oddness that others might sneer at but which he himself could respect.
"You both sound like men who see no wall as too high," Ryusei said, tilting his head. "That's the kind of spirit I admire. I'm still finding my way in taijutsu. Maybe one day I could learn a thing or two from your drills."
Duy slapped his thigh with a loud smack, grinning. "Spoken like a true youth! Determination shines brighter than talent. If you've got the will, you've already taken the first step."
Guy piped up, wiping sweat off his brow. "Father's right! If you believe in yourself, you can break through anything! Even if people laugh, you just keep running forward!"
Ryusei held his smile, eyes narrowing just a touch in the way the original owner had trained them to.
Inside, though, he noted carefully how to keep the conversation light, compliments, optimism, and eagerness for training.
Exactly the things that would sit well with this peculiar father and son.
"So," he asked, voice respectful, "how many laps do you run before the day ends?"
Guy's face lit up instantly. "As many as it takes! Want to join us?"
Ryusei didn't hesitate. He gave a small bow, then fell into stride beside them as if it were the most natural thing in the world.
The dirt was uneven, the river wind damp against his face, but his steps matched theirs quickly and lasted from beginning to the end.
Guy's eyes went wide when he realized Ryusei wasn't lagging over time. "You're keeping up already? Most people stop after a few laps around here!"
Ryusei kept his breathing steady, a faint laugh slipping out. "Running is easier when the company's good."
Duy's booming voice echoed across the riverbank. "Spoken like a comrade of youth! Few boys your age choose to embrace pain like a friend. Most fear it!"
Ryusei tilted his head slightly, still keeping that narrow-eyed, polite smile. "Pain's just proof the body's learning. If it hurts, it means there's something to gain from it."
Duy clapped his hands once, nearly breaking the rhythm of his run. "Yes! Exactly! A diamond only shines when struck. A body, a spirit—no different!"
Guy grinned, his sweat-slick hair bouncing as he looked at Ryusei. "So what are you training for? You must have some goal if you run like this."
Ryusei's voice stayed calm, but his words carried weight. "To become someone who won't lose to himself. If the body breaks, the will carries it. If the will falters, the body drags it forward. As long as both keep moving, I won't stop."
There was a silence for a stretch of the lap, only their steps and the splash of water as they cut across the shallow edge of the river.
Then Duy threw back his head and laughed heartily.
"That's the spirit! You're already a brother in training. From today, we're comrades on this path!"
Guy nodded fiercely, his voice almost cracking. "Right! From now on, we run together. No quitting!"
Ryusei chuckled quietly. "No quitting," he agreed.
As they circled back, the chatter grew easier.
Duy spoke about how he once trained until he fainted three times in a row, waking up each time to keep going.
Guy shared how other Academy students mocked his bowl-cut and his endless shouting about youth, but how he didn't care, because his father said that ridicule was proof he was walking a different road.
Ryusei listened, interjecting only with small nods and comments, but inside, he recognized something rare.
These two weren't fools. They lived by a principle most people were too afraid to test.
The more you struck iron, the sharper it became.
The more you pressed the body, the more the will was forged.
By the end of that first shared run, sweat dripping down their backs, none of them felt like strangers anymore.
They had all tasted the same logic and respected it.
His and Guy's feet finally slowed after what must have been close to hundreds of laps already.
The river breeze felt cooler now, almost pleasant against sweat-soaked skin.
Duy stretched his arms back, chest heaving, but his grin never faltered.
"Excellent! Excellent! The three of us, pounding the earth together—it feels as if the ground itself acknowledges our spirit!"
Guy collapsed onto the grass, arms splayed out wide, gasping but still smiling. "I… I thought you'd quit halfway, Ryusei… but you didn't! You're amazing!"
Ryusei crouched instead of dropping, rolling his shoulders once before settling into a calm posture.
His breathing was heavy, but steady, controlled.
He offered Guy a small smile. "Quitting halfway would've been rude. You invited me, so I had to finish beside you."
That simple line made Guy's eyes sparkle. "Then you're not just strong—you're polite too! That's double youth!"
Duy laughed so hard his shoulders shook. "Ha! Spoken like a true flame-blooded youth, Guy!"
He wiped his brow, then turned to Ryusei. "If you're willing, come back tomorrow. We'll burn the morning air together again."
Ryusei inclined his head, still wearing that narrow-eyed smile. "I'll be here."
***
Back at his home, Ryusei lowered himself into a steaming medical bath.
His body felt beaten from every angle, muscles trembling under the strain, but he welcomed it as he pressed his Mystic Palm across bruised spots, forcing his recovery forward.
He had learned more than expected today.
Their chatter by the river had drifted from drills to conditioning, from willpower to philosophy.
It was simple talk, but in those words, he caught glimpses of why people like Duy and Guy walked such an unusual path.
They probably liked him now, too—he could tell.
Most mocked or dismissed them, but he had been polite, listened earnestly, and even kept pace with their insane training.
Talent mattered, but so did iron will, and they recognized it in him the same way he recognized it in them.
Building a closer bond wouldn't be difficult from here on out.
Their taijutsu wasn't better or worse than the Senju style he practiced—it was just shaped differently. Suited for their bodies, their spirit.
His own path was cut for him alone. What surprised him most, though, was not only their discipline but a realization about himself.
Now it made sense. Why Duy, Guy, and later Lee, in the story he remembered, had endured daily torture-level training without collapsing into permanent injuries.
It wasn't miracle genes or reckless luck. It was the chakra itself. The constant cycle of small injuries, small healing, and small growth, all accelerated by chakra's presence in the body.
The energy that fueled ninjutsu was also the reason human limits could be stretched so far.
This was why constant extreme training worked here, unlike on Earth. It wasn't even close.
Ryusei had never been sure how physical training in this world compared to the systems he knew before, so he hadn't gone heavy into it after his transmigration.
Injuries had also kept him down for a long while, too, so he stuck only to light maintenance routines, the same ones the original owner practiced, but to an even lesser extent, from time to time.
He told himself he'd focus on the body later, after his other plans and habits were set and once he confirmed those things and healed all injuries.
Still, training the body was no less important than anything else, perhaps even more important.
A stronger body wasn't just for taijutsu; it was the cornerstone of 'physical energy' - part of chakra stamina.
Growing willpower, aka 'spiritual energy', alone wasn't enough; he needed his body to match it for more chakra reserves.
Puberty would push him forward naturally, but this was also the best time to push the upper limit even higher with smart training while his body was most adaptable.
Manuals were one thing, but he knew he needed real conversation to get anywhere.
That was what he got from Duy today.
Ryusei had asked him questions directly, not underestimating the man's "simple" passionate routines.
If he'd taken himself from a civilian's frame to one that could withstand the final Eight Gates, then he clearly understood body conditioning on a level few did.
The first lesson flipped Ryusei's past-world logic on its head: more was better here.
In this world, the body wasn't fragile the way he remembered.
Chakra made the difference. It healed and toughened the body after every strain, making daily abuse into growth.
That was why people like Guy could run until nightfall, collapse, then repeat the next day.
Why could they train with what looked like reckless abandon, year after year, for decades, yet never break down, and look healthier than ever.
Ryusei had seen it with his own eyes.
Duy was barely affected by what should have been superhuman workloads by Earth's standards.
Even Guy, at just ten years old, endured high-paced laps that were far beyond normal running, as he was quite used to them.
Ryusei himself, twelve and with a naturally stronger physique, barely kept up with just Guy.
And yet both of them looked like it was only another day.
He realized then how much of his old thinking had to be thrown away.
Duy had said to him that he had never once been injured from overtraining, not even in his youth.
He didn't know that such a concept as 'overtraining' basically existed, and was stunned when hearing Ryusei's previous logic about it.
The same was true for Guy.
Both of them had started with civilian bodies, nothing special at the beginning.
And if they could reach this level, then what did that say?
It was simple. There was no real limit to physical training here besides mechanical exhaustion.
The only wall was mental - the one that came way sooner than mechanical, true failure.
That was why iron-willed civilians like Duy, Guy, and later Lee could rise so high in this world.
Because they defeat literally the only obstacle day after day, which was their own minds.
They had found the secret others ignored: with discipline and inner strength, chakra turned even madness into progress.
But being like Duy and Guy wasn't something everyone could do.
Their kind of mental fortitude, patience, and refusal to give up no matter how much time passed or how many obstacles stood in the way, was something rare.
It wasn't just willpower or discipline.
In their own way, they were "geniuses" too, not gifted with kekkei genkai, but with a psychology built for pushing past human limits.
Ryusei felt like he understood them completely, yet he also knew he could never reach that same level himself.
That was fine. If he could be even half or a third as strong as them in overcoming those inner barriers, it would be enough.
With his sharper insight and the ability to work "smarter," he could climb faster than they ever did.
And maybe, just maybe, cut a few corners along the way.
"From tomorrow, a third of my daily regimen goes to pure physical training with them, as long as I'm not on a mission. This builds body, will, and soul at once. And I wasted this long without realizing? Reading something simply won't do that."
He clenched his fists, amused at how quickly their madness had rubbed off on him.
Being around people like Duy and Guy, you'd have to be blind or stupid not to feel motivated.
Unless you looked at them with the usual sneer of ignorance most shinobi gave them.
Understand them, and you could only admire them.
They were among the only few 'characters' Ryusei ever genuinely admired, in either life.
He usually preferred villains, their clarity, their ambition, but these two were an exception.
Pure, 'good people', yet still tolerable. Even likable. Why?
Because most of their philosophy wasn't about empty kindness, it was survival, strength, and defiance of limits.
That was a language Ryusei understood.
Unlike characters like Minato or Kushina, whose morals and 'goodness' only annoyed him, Duy and Guy never disgusted him.
Their morals didn't matter; their path did. And that path, insane training, iron resolve, crushing limits, fit perfectly with his own goal: survive, rise, and tear down fate itself.