Taisei, Touma and Aina all stood in the tiny cabin located somewhere on the outskirts of the Senju clan. Touma stood at a calm attention, while Taisei looked more like he was waiting for a tree to drop on his head.
"You and Touma will be responsible for showing Kotetsu how seals function."
Taisei's jaw dropped as Aina relayed the orders given to her. Touma's expression did not change in any significant fashion, simply resting in his standard ever-stoic face.
"We have to teach that barbarian?" Taisei sputtered.
Aina raised a single eyebrow.
"That's what my mother wants."
Taisei failed to find any words, giving Touma room to speak.
"How much are we expected to teach him?"
Aina shifted her gaze from the still open-mouthed Taisei to his father, answering promptly.
"Mostly the basics. From what little she told me, she simply wants Kotetsu to understand seals and how they work… and maybe other things, if applicable."
Touma scratched his chin while he thought. Meanwhile, Aina turned back to Taisei and shot him a question.
"Is this arrangement going to interrupt your own training?"
Taking a moment to gather himself, Taisei thought it over. In a gesture Aina found amusing, he mimicked his father by scratching his chin.
"No… I guess not. Even a barbarian can learn the absolute basics in a week or two..."
He paused his scratching to look down at his hand.
"...Assuming he can read."
"I'm fairly certain he can read." Aina reassured him.
Taisei snorted as he stared off into space. Touma asked another question.
"When should we expect him? I would prefer to begin as soon as possible."
Aina felt certain about her answer.
"Immediately."
—
Mutsue sensed her daughter approaching the cabin. After allowing the boy to go and cause a ruckus around the clan, she busied herself with one of her latest art pieces while sorting out some thoughts. Something had thrown her off since the conversation with the boy. Aina entered the cabin while she picked something apart in her head.
Neither said anything for a whole five minutes, both aware that they were attempting to wait out the other in their customary game. Aina eventually lost, and she began the conversation by loudly clearing her throat.
"...Touma is ready to receive the prisoner. He is still a prisoner, right?"
"Yes."
"I see."
Aina pushed down her initial spike of annoyance from the curt response and following silence. She could tell that Mutsue was deep in contemplation, and decided to try and guess the direction of her thoughts.
"So… how was that conversation this morning?"
Mutsue had remained where she stood in front of the incomplete clay vessel, her attention not particularly focused on any one thing. When Aina voiced her question, she glanced up and peered directly at her daughter.
"It was not what I expected."
Mutsue returned to inspecting her unfinished work, continuing her objective of ignoring her daughter. Before Aina felt the need to bang her head against the wall, she continued.
"The boy lacks much of what we consider fundamental, as you might have deduced."
She began to walk around the vessel as she talked.
"And yet…"
She hesitated. Closing her eyes, she inhaled a deep breath.
"Daughter… you remember what I told you, about Koyu Hoku and the tragedy with our people?"
Aina kept her initial reaction at the shift in topic to herself. Her second reaction wasn't much better.
"Uh… yep. It's kind of hard to forget that."
Mutsue didn't even bat an eye at her daughter's impudent reply.
"In the final moments of the fight, I had laid a trap below one of my fallen sisters. It had been imbued with as little Chakra as I could manage while still maintaining effective power. It would have been nigh-impossible for anyone to sense it in the midst of combat. However, Hoku dodged it."
As a matter of fact, Aina did remember this. She still failed to see the connection with the previous topic.
"Yes, I remember. You weren't sure how she knew it was there. Is it really that hard to believe that she could sense it?"
Mutsue waved away the question.
"There are other factors in play that have now convinced me otherwise. Truthfully, I have always suspected how she knew my attack was coming, but I simply lacked evidence."
"Other factors? So you have evidence now? How did she know, then?"
Aina realised she had jumped in with impatience, and received a baleful look in return. Her mother was not someone to speak over. Usually.
"She could see my attack, plain and simple."
Mutsue did not elaborate further. The silence stretched on for several seconds. Aina felt an uncontrollable twitch in her eye before her mother finally continued.
"I suspect that the boy, as well as his grandmother, both possessed some ability to directly see one's Chakra signature. In other words, the soul. I had the opportunity to test this with the boy earlier. And yet…"
Mutsue had continued her inspection of the clay pot while she spoke. Aina decided enough was enough at the latest pause.
"...And yet??"
With her back to her daughter, Mutsue smiled at having won the game.
"And… It's complicated."
"It's… complicated."
"Yes, that's what I said."
Aina took in a calming breath.
"Would you please explain?"
Mutsue turned away from the clay vessel to face her daughter fully. Aina saw the fleeting smirk on her mother's face.
"Did you sense the seal on him this morning?"
The whiplash-like shifts in conversation suggested that Mutsue really was working through something complicated. Leaning back against the wall, Aina folded her arms and replied.
"Yes. It was kind of hard to miss. What about it?"
"That was part of a test to see his accuracy with perceiving Chakra. As a result of an earlier predicament, I obtained partial evidence pointing at some ability to see Chakra, and so needed further testing. And during the application of this seal, he sensed my actions, and I presumed he saw my Chakra."
Mutsue ground her teeth as she thought. It was a tick that Aina had never seen her mother do before.
"So he can see Chakra." Aina concluded.
"Not quite."
Aina barely caught the troubled expression on her mother's face.
"From his perspective, the seal should have blinded him completely. However, he did not even appear to notice it… instead, it was the threads I used to apply the seal that he took notice of. He looked directly at my Chakra threads, daughter. He followed their winding path straight back to me, completely ignoring the seal which, at the time, spanned his entire head."
"I don't think that's how Chakra sight works…." Aina mumbled.
"It's not." Mutsue affirmed.
Both women looked at each other for a moment, thinking. Aina spoke before her mother could.
"What if he… simply ignored the seal? Maybe he knew you were testing him."
Once again, Mutsue waved away the thought.
"That doesn't make sense. He is not stupid, yes, but he is far from smart. Furthermore, I believe that this is a new development of his. Taking that into account, he should have been more drawn to the seal by simple curiosity. However, he did no such thing…"
Mutsue continued her silent thinking while Aina tried to think of a way out of the problem. The actual issue stemmed from the difference between the Chakra threads Mutsue would have used and the seal itself. Aina knew from earlier that the seal was constructed purely out of static Chakra. The threads, on the other hand, would have been made from active Chakra. Mutsue spoke first this time.
"Daughter… you and I both know what the difference is. The only thing separating active Chakra from static Chakra, is the presence of mental energy."
Aina began to examine what she knew in an attempt to refute the unspoken claim.
"None of that makes any sense. Something like what you're suggesting would imply some sort of ability completely outside of Hanao's Chakra model, or a wildly high level of skill in Chakra control, neither of which Kotetsu shouldn't have from my experience. Even though I only saw him fight once, nothing he did even vaguely indicates that he possesses more than basic Chakra control… from the moment he broke his restraints to the moment he passed out-"
"-Broke his restraints?"
A thought occurred to Mutsue. Days earlier, while questioning Aina about the events leading up to the boy passing out, they had skipped over how he broke his restraints. Mutsue failed to ask, and Aina failed to mention. Now, she realised that her assumption led to a misunderstanding. Aina waited to hear why Mutsue had interrupted her.
"Tell me, before his fight, when he– when… 'Kotetsu' broke free of his restraints, what happened?"
Aina didn't understand why it was important, but she could immediately recall the image of the shackles exploding as Kotetsu shunted them off with ease.
"It… Well, it was like they were made of glass. He caused them to shatter with an explosive shockwave of Chakra. He had already been making several attempts to break the restraints leading up to and even during the fight, but they all failed. He seemed to lack the Chakra strength, except for the final attempt. His pure strength over his own Chakra in that last attempt was rather abnormal, but otherwise, the action was…"
She fell silent after spotting her mother's rigid expression.
"...What is it?"
After a moment, Mutsue reigned in her reaction.
"You said… he used a shockwave of Chakra? Are you certain?"
"Uh, yes. I had my senses focused on him the entire time."
Mutsue walked away from the vase and began to pace back and forth across the room. Aina grew more worried at her mother's responses.
"Mother, what aren't you telling me?"
After a loop of pacing, Mutsue slowed to glance at her daughter.
"You sensed no presence of a seal, or any other sort of interference?"
"Uh… no. I would have noticed something like that. He used active Chakra, obviously. Again, what aren't you telling me?"
Mutsue did not respond, instead turning away to continue pacing.
"What were you expecting him to do, mother?"
Mutsue had made a foolish assumption days ago. Worse, her own senses corroborated with that assumption, and thus she failed to account for every potential factor. That mistake may have just cost her days of planning, and decades of theorising. She glanced up at the ceiling in self recrimination at her own lack of attention to detail.
"I… assumed that he reversed the shackle's seals. Something only possible to someone like him if he could interpret their function, which I also assumed he would learn using knowledge from his sword. I had specifically tuned his shackles to require a significant level of strength to break, more than he would be able to produce. Even with the amount of Chakra you told me he infused, it wouldn't have been enough to break them."
Aina had no clue what to say to her mother's rather grandiose expectations. After a time, she finally gave her intelligent response.
"...What?"
Mutsue began to discuss another point while she worked through her thoughts.
"You recall the function of the shackles, yes?"
Aina was still processing the previous statement, and simply nodded her head, recalling having to use the shackles in her own training years ago. Mutsue went on to explain things anyways, using it as a buffer while she resolved her thoughts.
"The seal works by forcefully un-infusing someone's Chakra. The resulting physical energy is then recombined with the seal's internal reserve of active Chakra. This works as described with Hanao's Chakra model, which includes the law that you may infuse anyone's physical energy with your own mental energy, making it your own Chakra. The reason this is relevant is due to the three known methods Shinobi use when breaking the shackles."
Aina furrowed her brow at her mother's wordage. She was only aware of two such methods, though she suspected that the third such method may be what Mutsue hoped Kotetsu had done. What bothered her was the usage of another word.
"Known ways? I thought the whole point was that those methods relied on how Chakra worked, so they are literally the only possible ways-"
"-I believe that the boy broke his restraints like an Asura breaks free of a seal." Mutsue interrupted.
After fully processing the disruption, Aina smiled at first at her mother's attempt at humour. Mutsue did not smile back. Aina's smile shifted to a frown as she truly considered the words. The realisation settled, and the implications became terribly apparent.
"But-"
"-I felt the defusing of my Chakra. Yes."
"Are you-"
"-Yes, I was completely aware of my control over his shackles."
"But what-"
"-This will go much quicker if you shut up and allow me to explain, daughter of mine."
Aina realised she had stepped away from the wall in her frenzied questioning, and took two quick steps back while breathing deeply. After reclaiming control over her emotions, she waited patiently for her mother to explain by aggressively bouncing one foot.
"As you know… The two most common ways one can remove their restraints are as follows. Either you directly break through the static Chakra barrier, pushing through and attacking the seal, removing the active Chakra within. Or, by improving one's control over their Chakra, allowing them to resist the un-infusing process, which results in the starvation of the active Chakra within the restraints…"
Aina did her best to remain silent as Mutsue took her time getting to the point, as usual.
"...Or finally, reversing the seal's effects with their own seal knowledge. If you have the knowledge, writing a seal with your own active Chakra is by far the least expensive method. It is also the least common method, which is why you are not aware of it."
Mutsue crossed her hands behind her back as she got to the real problem.
"However, I did not feel any collision of Chakra against mine as a result of expulsion, nor was the Chakra unable to un-infuse his own. Instead, I felt my control over the Chakra itself be removed. In effect, it was my Chakra that was un-infused. As you know, that exact effect is performed by the seal of the restraints themselves, which is why I had assumed that he reversed the seal's function back on his shackles..."
Letting her breath go, Mutsue sighed.
"...Leading me to the only other way he could have broken the seal. As we both know, Asuras directly attack mental energy itself, which is what he did. There is only one way he could have done that."
Aina refused the direction her mother's thoughts had gone. There had to be another way, she reasoned, so she laid out her own speculation.
"What you are implying should be possible… But, the only other explanation I can see would be that Kotetsu is utilising the same mechanism as an Asura, by taking direct control of natural energy. But that doesn't make sense, either. Chakra and natural energy are direct opposites, they are incompatible. It is exactly why we must constantly maintain static seals, and why all forms of Chakra not within the body or controlled by mental energy degrade. Taking all of that into account, there should be no way he could do anything you've claimed…"
Mutsue nodded her head angrily.
"I am well aware of these facts, daughter. Within our current framework, what he has done is theoretically impossible. Which means that our understanding of Chakra is either incomplete, or outright wrong."
Mutsue had stopped walking to stand directly before her daughter. Aina attempted to justify the anomalies, but Mutsue met her at every point.
"There has to be a better explanation for what he saw. Seeing active Chakra alone just doesn't make any sense." Aina began, but Mutsue countered.
"How could he only see my Chakra threads, and not the barrier placed upon him? The only true difference we are aware of is mental energy, but mental energy is supposed to have no effect by itself according to the current model. How, then, could he observe mental energy?"
"...Maybe there's another factor-"
"-How could he directly un-infuse my Chakra, separating my mental energy from the physical energy, without any kind of seal or technique?"
Mutsue took a step toward her daughter with each point, getting closer and closer.
Aina tried to reason again. "...You said yourself that the feeling was like an Asura breaking out of a seal, maybe we're wrong and he is using natural energy-"
"-The energy that is in direct opposition to Chakra, as you brought up, which by your admission he expelled at the same time he broke free of his restraints. And he possesses no Asura to manipulate natural energy with."
"...I just-"
"-Mental energy is only supposed to command physical energy according to Hanao's model. At his level of skill, there is no way he could have recreated the shackle's effect with pure Chakra manipulation alone. I did not feel any collision of Chakra, only the feeling of my mental energy being removed. Even if that means he somehow used his Chakra as a basis for the attack, he must have directly utilised mental energy to attack my own."
"But, it's-"
"-The only connecting factor."
Aina was silent for a long moment as her mother stood nearly directly in front of her now. She could not think of any way to dispute any of her mother's claims. Only one final thing came to mind.
"We… We need more data. All of this is purely hypothetical."
Aina watched as Mutsue pulled forward her rocking chair and gently took a seat, settling her chin atop both hands.
"Good. You understand, then."
"...Excuse me?"
Momentarily taken aback by her own statement, Aina forgot to not act capricious in front of her mother. Luckily, Mutsue seemed to ignore her daughter's sudden angry shift.
"You understand what must be done. Before we explore that, however, I need to explain some information which I feel is relevant…"
For the first time in their conversation, Mutsue smiled. Aina found it disturbing.
"Right now, we are claiming that 'Kotetsu' has some capacity to directly see mental energy. Everyone is capable of manipulating mental energy, as that is how we control Chakra, obviously. However, we are now postulating that mental energy is capable of interacting with itself. This would ironically fill the gap of natural energy being the only effector of mental energy in Hanao's model."
Aina's only option was to endure while listening to her mother's exposition.
"As for the relevant information, I believe that every Cinder possessed these skills to some degree. I foolishly assumed that the sword was providing intellectual knowledge to the boy, like reading from a book, but that is clearly not the case. Otherwise, I am confident that he would know more about seals by now. I am unsure in what method the information comes to him, but I now hypothesise that he is being reflexively trained in the methods of the Cinders."
Mutsue finished explaining the thoughts she had spent the better part of their conversation pulling together. Now that the words had been spoken, she was more certain of her own assertion.
Grabbing her chin, Aina contemplated her mother's claim. For the first time in the conversation, she stopped to carefully choose her words, instead of dramatically pausing.
"What do you mean by reflexively?" Aina spoke after a moment.
"Simply that he is not intentionally seeking out the information. However he is receiving that knowledge, it must be mostly reflexive, likely based on his current environment."
After another moment of thinking, Aina picked up her earlier question.
"To reiterate… How do you propose we acquire more data?"
Mutsue smiled inwardly as the hook sank in. It was much easier to make someone do what you wanted when they became invested in a shared goal.
"We will continue to shape his environment."
—
Kotetsu had been saved from another near-death scenario. After letting him consume a hearty amount of food, Rata attempted to corner Kotetsu for a duel right there in the small clearing full of Senju. Luckily, Taisei had found and pulled him away from the aggressive older Senju. Rata flashed a face filled with disappointment as he watched Taisei nearly drag Kotetsu away.
Some time later, Taisei and Kotetsu sat side by side in the room where it all began, facing Touma as he pulled together his notes. Taisei sat perfectly upright, his paper and writing utensil set straight before him. Kotetsu wriggled slightly, trying to get comfortable on the hardwood floor of their hut, his own writing implements scattered loosely in front of him. When Touma was ready, he patiently waited for Kotetsu to stop squirming before beginning his lesson.
"Seals and fuinjutsu, or sealing techniques, in basic terms, involves the usage of a physical medium to seal a physical object, Chakra, or to reproduce a technique."
Taisei did his best to not look bored. He told himself that this would just be for one or two days, then Kotetsu could start reading some texts. All of this was old news to him.
Kotetsu belatedly realised he was probably supposed to be writing down notes, and reached for his paper. His pencil was nowhere to be found. He glanced around in panic for several seconds, not finding it anywhere.
"When we create seals, the most common method is to use written characters. The seal language, as it is known, can nearly translate directly into handsigns."
Leaning over, Kotetsu whispered quietly at Taisei.
"Hey… can I borrow your pencil? Just for a moment?"
Taisei tried not to react. Turning his head so he was just barely facing Kotetsu, he whispered back.
"No."
Kotetsu turned back to his own paper, flipped it, then flipped it again. He glanced around, his panic rising more.
"Seals themselves are a representation of intent. Like handsigns, they convey a broad concept, which is then interpreted by the user and shaped to form their technique…"
Leaning back to Taisei, Kotetsu whispered again while reaching for his pencil.
"Look, I just need it for a moment, okay? I'll give it right back-"
"Hey-"
Taisei reached over and grabbed Kotetsu's wrist. Or at least, he tried. Deftly swerving over the reaching hand, Kotetsu managed to snag the pencil and began retreating with it. Taisei put both of his hands on Kotetsu's retreating arm.
"Give it back!" Taisei hissed.
Trying to rip his arm away, Kotetsu hissed back.
"Stop being stingy!"
Taisei reflexively argued back. The two went back and forth, their volume raising dramatically.
"I'm not stingy! It's my pencil, use your own!"
"I can't find it! Just let me borrow this one!"
"Nuh uh!"
"Come on-"
"Both of you need to stop." Touma's voice boomed out through the room, freezing the two boys in place. He pinched the bridge of his nose.
Kotetsu dropped the pencil, and Taisei smirked as he picked it back up, placing it back in its spot right by his paper… which was now crumpled. He glanced over to see Kotetsu's innocent face. While he was distracted, Kotetsu must have grabbed at the paper with his other hand. Taisei felt his blood pressure slowly rise.
Touma stared down at the heated scene with contemplation. He had not seen his son so worked up over something so minor before. Moving his hand from the top of his nose down to his chin, he considered what to do next. Kotetsu didn't seem like the kind of kid to respond well to passive lessons like this, and he needed to get things moving along quickly. An idea struck him, and he rubbed his chin thoughtfully.
Taisei noted the movement. Then, Touma spoke.
"Kotetsu…"
Looking up from his pencil-less hands, Kotetsu tried to look casual.
"Uh… yeah?"
"Move your legs."
Unsure of Touma's reason, Kotetsu absently lifted both of his legs slightly. His missing pencil rolled out from beneath his left buttcheek. He stared at it with a dumbfounded expression.
"Oh." He responded with a tone slightly higher than normal.
Grabbing the pencil, Kotetsu spun it twice, then put the tip to his paper. He kept it there for a solid four seconds, before looking back up at Touma.
"Could you repeat some of that?"
"I'll do something better. Follow me. Both of you. And leave the paper." Touma responded, standing from the chair he'd been resting in.
Taisei knew his father was up to something. He hoped that whatever the old man had in mind, it would be interesting for himself as well. Despite his earlier assurances, he was a little sour at not getting to learn about static seals right away.
The two boys glanced at each other before rolling to their feet and following the older man out of the door. Kotetsu and Taisei stepped up behind Touma to stand on a platform that served as a porch. Taking in the sight of the mid-afternoon sun falling through the redwood trees, Kotetsu sighed. His last visit through here had found him a little upside-down, so he didn't have much time to appreciate the view. He fully understood why the Senju clan preferred the high ground if it meant scenes like this.
Touma glanced off the edge of the porch, scoping out where he would be taking the two boys to begin his new and improved lesson. Then, a thought came to mind, and he took a moment to ask a pertinent question.
"Kotetsu, how is your wall-walking? We'll need to get down to the ground…"
Touma's sudden question caught Kotetsu off guard. It had only been a few hours since the old Matriarch had stopped questioning him, and in that time, he had done a lot of thinking. During his crazy flight through the forest to find food, he hadn't noticed his own wild movements, flinging himself around branches and haphazardly avoiding trees. Even after hindering his own knowledge of Chakra control for so long, his body seemed to have adapted to his new understanding of Chakra quite well. He vividly remembered that first day several years ago of him trying to learn how to wall-walk. That memory left him cringing as he now saw how much he had actively ignored. If he actually understood Chakra control from the beginning, he wondered if everything would have clicked sooner.
"Uh… Hello?"
Kotetsu snapped his attention forward, realising his daydreams had spiraled a little hard.
"Yep. I can wall-walk."
Touma seemed skeptical, especially after the long pause.
"Look… It's okay if you can't, I don't want to be responsible if you fa-"
Between Touma's words, Kotetsu took two steps to the side, instantly dropping off the edge.
"Shit-"
Taisei and Touma simultaneously yelped as they rushed to peek over the edge of the platform. They found Kotetsu standing sideways, protruding like a white-haired branch right off their hut's supporting tree. Upon seeing his casual stance, Touma smirked while Taisei scowled. Taisei pulled his head back from the ledge first, speaking as he did so.
"Even if he did drop and hit his head he'd probably be fine. Barbarians don't have much of a brain to hurt anyways."
Touma turned slightly to watch his son walk to the other end of the porch, where he began tapping his feet impatiently. Taisei asked his next question laconically.
"What next, father?"
Glancing between the two boys, Touma noted the perplexed expression on Kotetsu's face. At first, he thought it might be confusion from Taisei's action, but his eyes seemed to drift as if thinking deeply. At the same time, Taisei's expression grew more annoyed as the seconds ticked by. Touma was pretty sure he knew exactly what was bothering his son by that point. He hadn't planned on playing mediator, but if that was the role they needed, then he would do his part. As long as it fulfilled his Matriarch's will.
Kotetsu, meanwhile, was busy dealing with the ease in which his feet stuck to the tree. For the last two years, his number one issue when sticking to any surface had been time. He couldn't retain the specific Chakra circulation required for more than a handful of seconds. Now, through his newfound Chakra control, he could just… do it. The process became clearer thanks to his awareness of willpower. His Chakra circulated through his feet and partially into the tree, before curving back toward his foot. Very little Chakra was lost in the process, surprising Kotetsu. In effect, it created a force that acted like an anchor, or a fishhook.
He got stuck on the image of fish. It had been so long since he'd eaten fish…
"We're switching to trial by fire. I want to make sure that Kotetsu fully understands the nature of seals. And this way, we can get to creating static seals right away as well." Touma answered Taisei's question.
Taisei perked up at that statement. Kotetsu seemed to pay more attention as well. Just then however, before any further explanation or teaching could happen, Kotetsu's feet suddenly disconnected from the tree with a pop, and he began to plummet.
"OhuaAAGH-"
With flailing arms, Kotetsu reached out for anything to grasp onto. A mere two seconds into his fall, a branch found its way under his armpits, and he held on for dear life while gasping deep breaths. A branch that hadn't been there two seconds earlier. From above, Touma held both hands together in an unfamiliar handsign. Kotetsu breathed a sigh of relief, while Touma sighed in disappointment.
"One fall is… more than enough for one day…" Kotetsu grumbled, pulling himself up.
Still looking over the edge, Touma called from above.
"Are you alright, young man?"
After getting himself under control, Kotetsu looked up with a grin.
"Just fine…!"
A thought occurred to him, and he added, "Does the Senju clan do any fishing?!"
Touma arched an eyebrow. From somewhere behind, Taisei scoffed.