The following morning came, and with it another day of missions and training. Yohei had briefly tried to engage in Total Concentration Breathing during his shower, only to break into a fit of violent coughing that left him light-headed and gasping.
As expected, general fitness alone wasn't nearly enough for it.
He'd need to properly condition his body first – but a good starting point would be setting his alarm an hour earlier so he could go on early-morning runs up Hokage Mountain. It was... probably high enough that meditating there would be a huge help towards increasing his lung capacity.
Besides that, he made a mental note to purchase some gourds at the market when coming back home today.
In a way… that was his own version of the Rasengan training with water balloons, wasn't it?
The thought made Yohei pause mid-step as he picked up a large wooden barrel.
"Damn it."
His muttered curse didn't go unheard. Souma, who was beside him lifting his own barrel, glanced over with curiosity tinged with concern.
Yohei waved it off with a carefree smile. "Don't worry, big guy. Just remembered a chore I forgot about. Hopefully we'll get back early enough for me to do it before Mom gets home."
Souma's eyes widened in understanding, and he nodded solemnly in sympathy. "I wish you luck."
Yohei chuckled and went back to work.
Today's mission was far less interesting than the one from the previous day. A craftsman needed to deliver a shipment of wooden barrels to a brewery on the far side of the village – and his daughter, a young woman in charge of the business's logistics and administration, had decided that instead of renting a cart, she'd commission ninja to do the job.
Yohei was pretty sure she'd just wanted the eye candy of watching buff shinobi haul heavy loads around. The disappointment on her face when they showed up instead had been hilarious.
Still, the mission paid well, and it wasn't particularly exhausting – just monotonous and time-consuming. They'd also been explicitly forbidden from making bets on who could deliver the most barrels or finish the fastest, since Hayama-sensei was worried someone would get careless and drop one.
Which… fair enough.
But as Yohei leapt onto a rooftop, carefully balancing the weight over his shoulder and sticking to their pre-decided route, his thoughts drifted back to what had made him pause earlier.
The Rasengan.
The Rasengan.
The Spiraling Sphere.
The Halo Frozen Dessert Hair Whorl Jiraiya Twin Formula Sphere.
Yes. That jutsu.
The signature technique of Uzumaki Naruto in the future – almost as iconic as his Shadow Clones, or even more so, depending on who you asked.
The pinnacle of Shape Transformation. A jutsu acknowledged by both Jiraiya and Sasuke as being more powerful than the Chidori in its base state – and that was before Nature Transformation was even applied to it.
He knew how to do it.
Well – no. That was an exaggeration.
He knew how to learn it.
Pretty much everyone who had enjoyed Naruto in his other life knew how to learn the Rasengan. It was one of – if not the only – jutsu whose inner workings were methodically explained, step by step. On paper, it was simple.
Which was not the same thing as easy.
Yes, Naruto had managed to learn it in roughly three weeks – but Naruto was a chakra freak who could afford to fail again, and again, and again, and again until he got it right. Not to mention that he'd seen the technique firsthand, and that he was a genuinely monstrous prodigy.
There was also that minor detail about his soul being the reincarnation of a demigod who may – or may not – have created something very similar to the Rasengan on a completely absurd scale in the past.
Yohei wouldn't know for sure until he tried, but he doubted he'd be able to attempt it more than… what? Five or six times a day? Maybe more. Maybe less.
There was no way to know without testing it.
And he wanted to try.
The Rasengan was a monstrously powerful jutsu with insane versatility for something that looked so deceptively simple.
…Not to mention how cool it was.
But that was the problem.
He couldn't.
Oh, sure, there was the issue of scrutiny – if someone discovered he was learning it, that would bring complications – but realistically, only Jiraiya and maybe Kakashi would recognize the balloon method on sight. Actually using the jutsu in front of others was a whole different category of trouble, but he'd rather know a technique that could save his life and never use it than die because he'd been too cautious to learn it.
Not to mention that he could always wait until Naruto revealed it and then claim he'd copied it.
Maybe.
It wasn't the most convincing lie in the world – but it could work.
Maybe.
But no – the real reason he couldn't try it was that he was already buried under shit to do. There simply wasn't any more time in his day for additional training, and definitely not for something that would leave him completely exhausted for the rest of it.
Oh, he dearly wished he could just make clones and double the hours available to him – even if only for studying – but not only did he not know the Shadow Clone Jutsu, he wasn't even sure his chakra reserves were high enough that he wouldn't just drop dead on the spot from the sudden loss of chakra.
"Total Concentration Breathing is going to help with that," he murmured to himself.
If nothing else, the physical and mental cultivation aspects of it were bound to increase his reserves – probably more than enough for him to attempt the Shadow Clone. And once he had that…
Things would get easier.
If he could find someone to teach it to him, that was.
Yohei let out a long groan.
"Isn't this world supposed to be a shōnen?" he grumbled under his breath. "Why do I have to worry about training logistics?"
With a sigh, he pushed the thought aside and refocused on his task.
The sooner he finished, the sooner they'd move on to the second part of the day.
-~=~-
A few more trips across the village later, another visit to the Mission Desk, and a short break for a meal, Team 5 found themselves once again at Training Ground 12 – which seemed to have become a minor trauma for Ren, judging by the way he was glaring warily at the river.
Yohei resolved not to tease him about it.
… Much.
"Alright," Hayama-sensei said, clapping his hands together, "now that you're all rested, it's time we start today's training: chakra conditioning."
"We'll be dividing it into three parts. First: chakra control. We'll exercise it until your reserves are almost depleted, which will naturally lead us into the second part – chakra molding. There are few things as essential to a shinobi as being able to quickly and efficiently recover spent energy."
He held up a finger.
"And finally, Nature Transformation exercises. Understood?"
"Yes, sensei!" the team answered in unison.
"Good." Hayama bent down, picked up a stick, and drew the kanji "車"- for 'Chakra' into the dirt. "Before we begin, however, we need to understand exactly what we're working with. And that means asking a simple question."
He looked at them over his shoulder.
"What is chakra?"
"I'm sure the Academy has explained this to you – probably more than once. But since yesterday we focused on cultivating your bodies, it's only right that today we cultivate your minds." A faint smile tugged at his lips. "After all, this balance is the very root of chakra itself."
Around the kanji, Hayama drew the outline of a human figure, positioning the symbol at its midriff. On the upper left side of the body, above the shoulder, he added a tomoe, then mirrored it on the lower right, beneath the hand. Within each curved shape, he inscribed the symbols for Physical Energy and Spiritual Energy.
"Chakra is a substance," he said as he worked, "one that is both part of nature – and above it. You'll often hear that it 'exists in all things,' which while not wrong, can be misleading. To truly understand chakra, you must first understand its components."
He tapped the two tomoe with the stick.
"First, keep this in mind: every living being is composed of two parts – the body, and the soul."
He gestured to the upper tomoe.
"The body is material. It is a biological machine in constant motion."
He spoke steadily, methodically.
"At every moment, it is breaking down fat to keep you warm, splitting sugars to feed your muscles, straining impurities from your water, filtering toxins from your blood. Your heart contracts and relaxes without pause, pushing blood through your system. When you are wounded, platelets rush to seal the injury before you bleed out. Every movement – walking, training, tensing in fear – is the result of countless muscles tightening and releasing in perfect coordination."
He rapped the stick lightly against the ground.
"Even standing still requires effort. Your posture is maintained by innumerable tiny corrections, fibers firing and relaxing so you don't collapse under your own weight. Breathing itself is labor. Your lungs expand and contract, air is drawn in and exchanged for carbon dioxide, and energy is released. Each breath feeds the fire of your cells."
He glanced at them.
"And sleep does not stop this process. While you dream, damage is repaired. Proteins are rebuilt. Memories are stabilized. Hormones are released to regulate growth and recovery."
He drew a short line beneath the upper tomoe.
"All of this – every contraction, every exchange, every renewal – creates Physical Energy."
Then he shifted the stick to the lower tomoe.
"The counterpoint to this," he continued, "is your soul."
His tone hardened slightly.
"This is your immaterial self – your spiritual construct. Save for certain jutsu that you should never meddle with–" he fixed them with a sharp glare until they nodded stiffly, "–your interaction with the soul should be limited to understanding that it exists, and how it contributes to chakra."
He straightened.
"Your body, for all its complexity, has no self-determination beyond instinct and biological regulation. When you think of your self, what you are actually perceiving is your soul. Your personality. Your thoughts. Your imagination. Your dreams, desires, fears – these are all aspects of it."
He paused, then added evenly,
"Your two halves are intrinsically linked. Every action taken by one is reflected in the other. In practice, this connection is most often mediated through the brain, which acts as a bridge between body and soul."
The stick moved in small, precise motions as he spoke.
"Every time you become aware of yourself – when you focus, concentrate, reflect, or engage in introspection – when you contemplate, reason, analyze, judge, evaluate, deliberate, or plan – these are acts of the soul."
He underlined the lower tomoe.
"And from those acts is born Spiritual Energy."
Cupping both hands together, Hayama continued, "When you consider those two energies as a whole, we call it Stamina – or Life Force. But something is still missing. What is it?"
He glanced between his students.
Ren and Souma exchanged a look, and Ren – clearly catching Yohei's barely contained eagerness – let out a sigh, rolled his eyes, and flicked his hand in a go on gesture.
Yohei shot him a grateful smile before answering.
"They're together," he said, "but they're still two separate things."
Hayama chuckled at the exchange and relaxed, resting his forearms on his knees.
"Good. Elaborate."
"Well…" Yohei took a breath. "In their natural state, Yin and Yang just… exist. They don't really do anything. That's where the Chakra Pathway System comes in."
"And that is?" Hayama prompted.
"The Chakra Pathway System – also called the Chakra Network or Meridian System – is a special organ that's both physical and spiritual," Yohei said. "It works somewhat like the cardiovascular system. It draws Physical Energy from the body's cells and Spiritual Energy from the soul, then guides both into specific organs, in special the heart, that function like… furnaces. Or crucibles."
He gestured vaguely with his hands as he spoke.
"Inside those, the two energies are mixed and refined until they stop being separate and become a single substance: Chakra. The system also includes the Tenketsu, or pressure points – three hundred and sixty-one nodes spread throughout the body. They store chakra, regulate its flow, and allow it to be expelled outside the body."
"Well said," Hayama praised with a nod. "That's an excellent overview."
He straightened slightly.
"Of course, we could spend days discussing each of those elements in detail, but for what you'll be doing today, this understanding is sufficient. So let's move on to the next topic."
He tapped the ground once with his stick.
"Using Chakra."
"The most basic application of chakra is a technique you may know by several names: Chakra Amplification, Chakra Enhancement, Flow State, or simply Strengthening, depending on who taught you. At its core, it is nothing more than actively circulating chakra through your body, reinforcing its natural functions – making you stronger, tougher, and faster."
He raised a finger.
"But remember what I told you earlier: chakra is both part of nature and above it. That distinction matters, because chakra breaks the natural laws."
He let that sink in.
"When you mold chakra, the result is not one plus one equaling two. It is one plus one equaling five. When you flow chakra through your body, you are not merely doubling your strength relative to the energy you invest – you are multiplying it by an entire order of magnitude."
A faint smile tugged at his lips.
"And that's without even accounting for the fact that, for some people, the 'ones' they bring to that equation are closer to 'twos'… or 'threes'… compared to everyone else."
"As an addendum," Hayama continued, "this technique can be taken to its logical extreme. If simply circulating chakra through the body enhances physical ability… what do you think happens when you flood it?"
He extended one fist.
Chakra surged outward, emerging from his skin and coalescing around his arm. Like most chakra Yohei had seen, it resembled a living flame – but Hayama's burned a smoky white-gray.
"This," Hayama said calmly, "is known as Chakra Enhanced Strength."
He rose to his feet and walked toward the nearest tree – an old, thick trunk so wide that all three genin together would almost struggle to wrap their arms around it.
He drew his fist back.
BANG!
The impact sounded like an explosion. Bark shattered outward as Hayama's fist drove clean through the trunk, leaving behind a smoking, ragged hole. The tree groaned – a deep, tortured sound – before beginning to tip and collapse.
"Do not get lost in awe," Hayama said sharply, snapping their attention back to him.
He raised the hand he'd used to strike.
The skin had turned an angry red-purple in patches, the fingers trembling faintly.
Yohei winced. Ren hissed through his teeth. Souma's brow furrowed deeply.
"Not a pretty sight, is it?" Hayama said flatly. "Good. Engrave it into your minds."
He clenched his fist once, slowly.
"Your body has a limit to how much chakra it can safely contain. That limit differs from person to person. When you exceed it – by doing something as reckless as overloading a single limb – this is the result."
His gaze hardened.
"This is not a technique to be attempted without exemplary control over one's inner energies. And it is certainly not something to be used frequently."
Souma hesitated, then asked, "What about Yohei's technique?"
His eyes flicked toward his teammate, concern plain on his face. Ren followed suit, curiosity clear in his expression.
"It's not quite the same," Hayama replied after a moment. "Though I suspect the underlying principles are similar. That said–" his eye sharpened slightly "–it is rude to ask a fellow shinobi for the details of their techniques when they are not public knowledge."
"It's fine, Sensei," Yohei said, cutting in with an easy smile. "I trust everyone here."
'To a certain point', he added privately.
"Besides," he continued aloud, "anyone with a decent understanding of Yang Release can make an educated guess about how it works."
Hayama studied him for a moment, then nodded, a faint, appreciative smile touching his lips. Yohei saw the same emotion mirrored on Ren and Souma's faces.
"In that case," Hayama said, gesturing lightly, "go ahead."
"Alright," Yohei began, rubbing the back of his neck, "to start with – my jutsu, Extreme Muscle Assault, is technically an Elemental Release of the Yang attribute."
Souma frowned, clearly confused, but nodded for him to continue.
"Normal elemental releases," Yohei explained, "work by molding chakra to imitate aspects of nature – fire burns, lightning pierces, wind cuts, yadda, yadda. But Yin and Yang Release – sometimes called Dark and Light Release – don't imitate nature. Instead, when you mold chakra that way, you alter the proportion of Physical and Spiritual Energy within it, making one dominate the other."
"But doesn't chakra need both to be balanced to work?" Souma asked.
"Usually, yes," Yohei conceded. "That's why it takes a lot of… force isn't quite the right word. Finesse, I guess? You're forcing two unequal things to behave as if they were equal."
He thought for a moment. "It's like trying to fit an elastic ball into a hole that's too small. You can do it, but only by carefully squeezing it in so it doesn't rebound. While if the ball were smaller, it'd fit naturally."
"Think of it like putting on clothes that are a few sizes too small," Ren added cheerfully.
Souma nodded slowly, understanding dawning.
"Exactly," Yohei said with a grin. "Yang Release is unique in how it strengthens and revitalizes the body. When I use Extreme Muscle Assault, I circulate Yang-aspected chakra throughout my entire body, and only then flood it with normal chakra."
He flexed one arm slightly, remembering the sensation.
"What stops me from tearing myself apart is that the technique temporarily reinforces my body so that it can withstand that amount of energy. That's why my muscles swell when I use it, it's the technique making the vessel bigger to be able to fit more inside."
"In a way, it is a mirror of Lady Tsunade's technique," Hayama interjected calmly. "Rather than refining your control and awareness of your body to the point where you can feed each individual cell the exact amount of chakra it can endure – achieving monstrous strength without injury – you increase the body's capacity instead."
His visible eye sharpened slightly. "But you do understand the drawbacks of this approach, don't you?"
Yohei nodded without hesitation. "It doesn't solve the issue of control. Even if my body's threshold is higher, it still has a limit. If I exceed it, I'll injure myself just like anyone else. And maintaining the technique for too long puts a serious strain on my muscles."
"Good," Hayama said with approval. "Never forget your weaknesses. They're the foundation for overcoming them."
He straightened slightly. "Now then – on to the second most basic application of chakra: expelling it from the body in its raw form."
His gaze shifted to Souma.
"Of the three of you, I believe you are the most familiar with that principle, aren't you?"
Souma nodded firmly. "It's the basis of Chakra Flow."
"Precisely," Hayama said. "Anyone trained in chakra can expel it through their tenketsu – most commonly those in the hands or feet, as they're the easiest to access. In this state, chakra behaves less like a substance and more like a force. Much like a magnet, it can attract or repel depending on the frequency it's tuned to."
He gestured lightly with one hand.
"Chakra Flow is an advanced application of this principle. A shinobi expels chakra through their hands, imbues the weapon they're holding in a manner similar to Chakra Enhancement – which works better on certain materials, though we'll cover that another day – and then coats it in a mantle of repulsive chakra."
He paused for emphasis. "In blunt weapons, that chakra spreads outward, reinforcing impact. In bladed weapons, it compresses instead, becoming thinner and sharper."
Hayama glanced at his own hand. "Of course, this principle isn't limited to weapons. Earlier, when I demonstrated Chakra Enhanced Strength, some of my chakra that had escaped from my control formed a similar mantle around my fist – much like what you'd do with a club. That helped protect my hand from even greater damage."
He turned slightly toward Yohei. "On the opposite end of the spectrum, it's also possible to coat your hands in sharpened chakra. Isn't that right?"
"Chakra Scalpels," Yohei answered with a nod.
"Yes. A notoriously difficult technique, primarily used by med-nin for both surgery and self-defense." Hayama smiled faintly. "Thankfully, what we'll be practicing today is nothing nearly as demanding."
He straightened. "Rather than working with chakra's repulsive aspect, we'll focus on its attractive one – in a technique known as wall walking. Or, in this case…"
His gaze flicked to the trees around them.
"…tree walking."
From the corner of his eye, Yohei caught Ren smirking, though he quickly suppressed it.
"In the past," Hayama continued, "shinobi expelled chakra from their hands and feet to adhere to surfaces – useful for climbing mountains, castle walls, or similar obstacles. Over time, this crude method was replaced with a superior form. Its mechanics are more complex, but the difficulty remains roughly the same."
He tapped the ground with his foot.
"What you'll learn to do is expel chakra from your feet, tune it to an attractive frequency, and then guide the rest of your body's chakra to align with it at the same coordinates. The result is a force that overwhelms gravity's hold on you and effectively reorients your axis."
Yohei frowned down at his own feet, brows knit, while Souma stared blankly ahead.
Seeing their expressions, Hayama laughed and waved a hand dismissively. "Don't worry if that didn't make sense. You'll understand it through practice."
He reached into his pouch, pulled out three kunai, and tossed them onto the ground in front of the genin.
"Your instructions are simple," he said. "Pour chakra out of your feet and run up a tree. Too much, and you'll be blown off. Too little, and you'll slide back down. Use the blades to mark your progress, and do your best to reach the top."
The three of them stood and picked up their kunai.
As they did, Ren turned to Yohei, eyes glinting with challenge.
"Up for another wager?" he asked.
Yohei lifted an eyebrow.
Ren snorted, grinning. "What, you're going to chicken out? It's just like yesterday, isn't it? I've got the best control, Souma has the most practice, and you've got the biggest chakra reserves. Each of us has a different strength here." His grin widened. "Besides – 'so long as you don't come in last, you don't lose'. Same bet as before: last place pays for snacks after training, first place gets bragging rights."
Yohei gave Ren a knowing look, a smile slowly spreading across his face.
It took the smaller boy only a second to realize it.
Ren clicked his tongue, grin still in place as he looked away, already about to say something – but Yohei cut him off.
"Sure," he said easily. "It's a deal."
Ren's head snapped back toward him. "What?"
Yohei chuckled and shrugged. "I said it's a deal. Let's do it."
Ren stared at him with narrowed eyes… then his expression fell completely flat.
"You know I'm going to win, right?" he asked.
Yohei nodded.
"And you're only agreeing because you want me to get a win after losing yesterday," Ren continued, unimpressed.
Another nod.
Ren sighed, dragging a hand down his face. "You do realize that you being all altruistic about this completely ruins my fun, right?"
'Oh, absolutely,' Yohei gloated internally.
Outwardly, though, he put on the most innocent expression he could manage and placed a hand on Ren's shoulder. "We're all winners here."
Ren's eye twitched.
It twitched harder when Souma stepped up behind him and placed his hand on Ren's other shoulder, smiling encouragingly.
Ren slowly shifted his gaze between Souma and Yohei, glaring daggers at the latter – before finally giving up with a defeated sigh.
"…Thanks, Souma," he muttered, then walked off toward the trees.
Yohei turned to the white-haired boy, the two of them exchanging amused looks.
Behind them, Hayama watched the trio with a nostalgic smile, rolling his eyes fondly at their banter.
Standing in front of his chosen tree, Yohei took a moment to think through his approach.
Last time he'd tried this, he'd pushed chakra through his feet too early – and with far too much power. The result had been spectacularly humiliating: he hadn't even managed to step onto the trunk, instead blasting the ground apart and launching himself face-first into the tree.
This time, he'd use less chakra.
And he'd only start once his foot was already on the bark.
"In my mark," Hayama called out, drawing their attention. "Three. Two. One – go!"
Yohei moved exactly as planned, avoiding the shame of repeating his first attempt. For a brief moment, he even convinced himself that the traction of his sandal against the bark meant he'd done it right –
BANG!
A loud explosion of sound and flying bark announced Souma being blown clean away from his tree.
Just a second later, Yohei felt his own feet start to slip. He slid a few meters upward before gravity reclaimed him entirely, and he dropped back to the ground like a sack of trash – his ass being the only thing to break the fall.
"Ow–! Motherf–!"
…It wasn't much of a cushion.
"You know what?" Ren said cheerfully, turning around. He was standing perfectly horizontal on his own tree, looking down at his teammates with a wide smirk. "I've changed my mind. This is still fun."
Clap. Clap. Clap.
"Congratulations, Ren," Hayama praised as he applauded. "It seems your family has already gotten a bit ahead in teaching you more advanced chakra control exercises."
The boy's smile turned bashful, a faint blush creeping up as he scratched his cheek with a finger. "Yeah…"
"That's wonderful," their sensei said warmly, eyes closed in satisfaction. "That means you can move on to the next step: water-walking."
"Heh, thanks – wait, what?"
Hayama's smile didn't waver.
"Water-walking," he repeated, lifting a hand and pointing his thumb over his shoulder – toward the waterfall they'd been swimming in yesterday.
Ren's expression went distant, as though reliving wartime trauma.
From his spot on the ground, Yohei barely managed to hold back his laughter, earning a sharp glare from the red-eyed boy.
Ren turned back to Hayama with a pleading expression, despair leaking into his voice. "Sensei… you're not still mad about that thing during the test, are you? It was just your clone!"
Hayama laughed and waved a hand dismissively. "Of course not, Ren-kun. Don't you remember what I said back then? You were just doing what you had to do. And now" – his smile sharpened just a little – "I'm doing what I have to do to push you past your limits."
"So you are mad!" Ren shouted, dropping to his knees – which looked especially ridiculous considering he was still standing sideways on the tree.
"Ganbare, Ren-kun!" Yohei cheered, laughing openly now.
"Ganbare!" Souma echoed.
"I'm going to kill you two…" Ren muttered, fighting back tears.