Have you ever been in a real fight?
I remember my first one back in middle school.
I don't remember what started it, but I remember how it played out. I had this vague idea—probably from watching too much anime—that fights had some sort of flow, maybe even a bit of technique. Nothing ridiculous, of course. No shattering of walls with a single punch or bleeding out like a dramatic final boss. Just… something structured.
It was nothing like that.
Throwing punches was exhausting. A few swings in, and I was already gasping for air, my arms burning from the effort. My opponent wasn't doing any better—we were just two clueless kids, flailing at each other until our energy gave out.
And then, mid-fight, a weird memory popped into my head.
'Huh? What's this…?'
A vague recollection of a YouTube video I once scrolled past:
[How to Breathe While Fighting]
I had scoffed at it back then. Breathing? What's that got to do with punching?
By the time our classmates pulled us apart, I had learned something valuable—not about fighting, but about breathing. And how I had been doing it all wrong.
So, as soon as the day ended, I rushed home and pulled up that video.
Breathing to preserve stamina. Exhale when attacking. Inhaling while defending. It wasn't just about fighting.
Think about the gym. The first time you step in, you just start lifting with no technique and no strategy. You just grab a dumbbell and swing it up and down, burning yourself out way too fast. It's the same with machines like the leg press or chest press—you push with all your strength, only to tire out almost immediately.
Turns out that breathing plays a crucial role there, too. If you inhale while exerting force—like pushing against the leg press—you burn way more stamina than if you exhale at the right moment.
It's not just fighting or lifting weights. Exhale while throwing a punch. Keep short, sharp breaths while sprinting for a short race. Take slow, deep breaths for endurance in a marathon. The more I thought about it, the more I realized that breathing isn't just something you do. It's something you use.
Martial Arts in real life, like Qigong and Aikido, followed the same concept. They mainly work by breathing in deep, rhythmic breathing that increases oxygen intake. The diaphragm then contracts and expands gently, "massaging" the internal organs and "pumping" the muscles, increasing the rate of flow of blood within the body.
Qigong also activates the parasympathetic nervous system, which is responsible for healing and recovery. It reduces muscle stiffness, allowing better nerve function and circulation and higher neuroplasticity, which improves the body's ability to adapt and heal.
It's basically the real-life version of Total Concentration Breathing. Sure, you won't be moving faster than sound or slicing through buildings, but it's still better than nothing.
Total Concentration Breathing takes these real-world breathing techniques and amplifies them, pushing the body's efficiency to its limits. Then, Total Concentration Constant takes it even further—turning controlled breathing into a nonstop, second-nature process that enhances every movement, every reaction, and every ounce of strength.
Strength, speed, defense, reaction time, even thinking capacity and the immune system—everything is amplified dozens of times through Total Concentration Constant. By maintaining controlled breathing at all times, the body operates at peak efficiency, maximizing muscle output, sharpening reflexes, and heightening awareness beyond natural limits.
Let's put it like this: an average human has a reaction speed of around 250 milliseconds. However, someone with Total Concentration easily has a reaction speed of merely 70 milliseconds, and someone who has mastered Total Concentration Constant has a reaction speed of only around 10 milliseconds.
Do you know how fast that is? A cat has a reaction speed between 20 milliseconds and 70 milliseconds.
If you wanted to catch an object at the speed of sound, you would need a reaction speed of around 3-4 milliseconds.
The Hashira possibly possess an even faster reaction speed, however, I have not reached that level and have no idea. Though, I'm fairly sure they possess a reaction speed in the single digits.
But Total Concentration isn't the only way to get stronger.
I lay on the ground panting as I looked at the sky. My eyes flicked over to my body covered in training robes. In just a second, the robes were replaced as my eyes pierced through them and saw my muscles.
Strained, swollen, twitching. Every fiber, every tendon, laid bare under my gaze. Torn and healing. Breaking and rebuilding.
Martial Techniques.
Martial Techniques were basically the combination of Martial Arts and a breathing technique.
I would like to tell you, that isn't a real word. I just made this up because saying Martial Arts with Breathing techniques was too long.
Its premise was simple: using martial arts along with a breathing technique. Since breathing techniques were mainly meant for enhancing the body, it was no problem incorporating martial arts within it.
Easier said than done though, learning a breathing technique was difficult enough with an average person needing around 4 years to learn one, and then adding martial arts on top of it?
Utterly impossible, most slayers don't live long enough to master both of these, and those that do become so attuned to their swords that they are no longer able to pursue the path of the body.
So it was no surprise that my master, who was currently the only person on that path, was an absolute monster
'This guy, he went easy on me' before
My eyes flicked over to my master, who stood before me. Though he looked calm, my eyes easily saw his irregular heartbeat and the panting of his lungs.
'That's it?' My eyes narrowed as I scanned his body. 'Not even sweat?'
To explain what happened, Kenzo Itsushi, my new master and my 3rd teacher, asked me to spar with him on the first day of teaching. I don't know why; maybe it was to establish a student-teacher relationship or to show me his full strength. I didn't care; any form of fighting was welcome to break my body down to perfection.
it wasn't a fight, it was a fucking sweep.
My eyes, capable of perceiving literal sound waves, could only see Kenzo as a sort of blur, like how Savitar appeared to the Flash. The match barely went on for a minute before I was down, sprawling on the floor.
The spar only lasted a minute because of the fact that I could sometimes predict his moves by the way his muscles contracted with my STW. Even then, it was hard to see him, so that trick didn't work most of the time
The major reason however were my monstrous instincts. Most of the fight, my body was just moving on it's own trying its best to avoid all of his attacks with my eyes and my brain barely keeping up.
"Your instinct is amazing," Kenzo muttered as he stood in front of me, offering me a hand "It's like you were born just to fight."
"I wouldn't be surprised if I was."
I grabbed his arm, using the momentum to pull myself up. But the moment my feet found solid ground, I twisted his wrist sharply, aiming to force him into submission before he could react. A classic joint lock—quick, efficient, and painful if executed properly.
For a split second, I thought I had him.
But...
Nah.
Instead of resisting, Kenzo flowed with the motion like a river bending around an obstacle. His body rotated smoothly, neutralizing the torque of my grip before redirecting it. I barely had time to register the shift before my entire arm was wrenched backward at an unnatural angle.
Pain flared as my shoulder locked up, my body instinctively freezing to avoid dislocation. His grip was like steel—unyielding, unbreakable. I gritted my teeth, trying to adjust my stance, but he applied the perfect amount of pressure to keep me off balance.
"OW OW OW STOP, I CONCEDE"
"...Looks like your pain tolerance needs some work as well"
Kenzo sighed, letting go of my arm, which I immediately took back and held, as I winced in relief.
'This guy's at the minimum as strong as a Hashira'
"That should give you a good idea of the power disparity between us, so don't let yesterday's victory get to your head. You're still far from approaching a Hashira's strength."
"Right."
Kenzo arched an eyebrow. "You're a man of few words."
I rolled my shoulders, wincing slightly at the lingering soreness. "You should learn to talk more," he added, watching me closely.
"Yeah, I'll try," I said dismissively, then met his gaze with renewed determination. "Can we get to the training already?"
Kenzo let out a short laugh, amused. "Already?"
Of course, already. He just showed me another path for getting stronger. How could I not want to learn it immediately? How could he expect me to wait? My blood began to boil from excitement the moment the spar started.
Fuck, I'm becoming a battle junkie.
"What's next?" I said, my voice barely containing my excitement. "Martial Arts need lifelong dedication, right? So I think we're going to start with something basic like Conditioning? Or maybe some stances? Some kata?"
"We should start off by checking your brain," Kenzo remarked. "Perhaps I hit you too hard."
"I can assure you, there was always something wrong with my brain."
"Well, then maybe I shouldn't teach you" Kenzo retorted joking.
I stared silently at Kenzo as he said that.
"What?" Kenzo asked
"No nothing," I said, shaking my head, though inwardly, my thoughts were different
'is he pretending that we never had the argument?' I thought as I replayed the conversation in my head 'Or has he moved on already? No, that can't be, he doesn't look that forgiving.'
'...Oh, he just vented all his frustrations by beating me up earlier'
"Before we train, there's something you need to know." Kenzo's voice was steady, but his expression had hardened. "You use Water Breathing, right?"
"Yeah?"
"I do too," he said, straightening up. "Tell me—have you noticed anything strange when using it?"
"Strange?"
"I'm talking about your mind—your thoughts. Have you felt… sharper? More aware?"
I frowned, thinking back. "Maybe a little? But it's not like some sudden enlightenment. Just a natural result of being in better shape—like how athletes have quicker reflexes and better decision-making."
Kenzo nodded slowly. "That explains it, then."
"Explains what?"
"The side effects." His voice dropped slightly. "It's not just from Total Concentration Constant. It's because I combined it with Martial Arts."
I stiffened. "Wait—side effects?"
Kenzo exhaled. "Yeah. I learned Martial Arts first, then picked up Total Concentration later. I always assumed the changes I felt were just from breathing techniques alone. But after watching you, I know now—it's the combination of both."
I narrowed my eyes. "What kind of side effects are we talking about?" ( -_- )
Kenzo raised a hand and tapped his temple. "Your brain," he said quietly. "Ever since I started training like this—combining Martial Arts with Total Concentration—something started changing up here."
"…Like… a tumor?"
"No dumbass"
"It's like" He paused, clicking his fingers continuously, searching for the words."How do I explain it? At first, it was subtle. I reacted quicker. My perception got sharper. I could read people—see attacks coming just by the way their muscles shifted. Like my brain was syncing with my body in ways it never had before."
"So," I said, processing the information, "Your mental functions got enhanced?"
"Indeed," Kenzo said, slapping his fist on his palm. "That's what I was trying to say. I always get confused while talking because my mouth can't keep up with my thoughts."
"That's...exactly what I need." I muttered, "You have no idea just how big of a problem you solved for me"
"Huh?"
My brain was by no means slow. Even before Total Concentration Constant, the me in the MHA world had a decent brain, possibly due to the upgraded physique of that world and the fact that I had utilized my brain most of this life studying and learning everything about the support class, and even that was enhanced when I acquired the physique of this world.
Infact, the comparisons I was making to the average person when I was comparing my strength, speed and thinking capacity to was just the actual me from the real world who was just a normal ass human.
But...even that wasn't enough.
My instincts had gotten so terrifying that my brain was no longer able to keep up with them. While that's usually not a good thing, there were some exceptions where I wished I could have controlled my body before it reacted.
Maybe then, there would be one more person still alive.
Maybe then, there would be at least one more family that never broke apart.
I never showed it, but the guilt gnawing within me was immense, and it didn't look like this was one of the things that time could heal. Losing human lives wasn't a concern...Taking them was.
My resolve was weak, to be shaken by the death of a single human whom I had never known? How was I supposed to go to other worlds and face threats like this? I was slowly becoming afraid of doing so...
...No. That was a lie.
What I feared most wasn't death. It wasn't even killing.
It was losing control.
Its obvious that as I travel to more worlds, I would integrate more physiques, and my monstrous instincts would only grow. At one point, it may reach a point where my body would move on its own, with my mind unable to do anything but think and lament.
So, the fact that I had somehow stumbled across a solution to that problem? The sheer relief I felt flooding my being was greater than any relief I had felt in both my lives, not that I remember anything of this life.
"That's all I need to hear" I said with a genuine smile "We're not wasting any more time talking"
...
...
...
I LOVE THIS
I looked at my blood vessels, my muscles, my entire body—warping, adapting, strengthening at an alarming rate. Every fiber of my being was being torn apart and rebuilt, reshaped by the brutal demands of Martial Techniques.
What Total Concentration would take an entire week to accomplish, this training forced upon me in a single day. My bones ached, my muscles screamed, and yet, I could feel it—growth. Pure, undeniable growth.
"MORE!" My voice tore through the air, raw and desperate. "I WANT TO LEARN MORE! I WANT MORE STRENGTH, MORE KNOWLEDGE!"
Kenzo's gaze darkened as he took in my state—my body shaking, my breath ragged, my muscles twitching from overuse.
"Kid…" he muttered, watching me carefully. "Training's over. You haven't eaten all day."
"I REFUSE!" I roared, my body burning with a maddening euphoria. The sheer power coursing through my veins made everything else feel insignificant. "EATING AND SLEEPING ARE A WASTE OF TIME! EVERY SECOND NOT TRAINING IS A SECOND WASTED!"
Kenzo exhaled through his nose, his expression unreadable. "I've trained countless disciples, but never have I seen one like you," he muttered, almost to himself. "Most of them tried to run, this is the first time I've seen someone trying to kill themselves."
"FOOLS!" I spat. "HOW CAN THEY EXPECT TO REACH GREATER HEIGHTS IF THEY FEAR THE PAIN IT TAKES TO CLIMB?!"
Kenzo sighed, rubbing his temples. "Calm down, You're starting to sound like the main character of a Chinese cultivation novel."
Calm down? How could I? My body was on fire with growth, every nerve screaming for more. The path to strength was right there, within reach—I just had to keep pushing.
Kenzo sighed again, this time rubbing his forehead as if dealing with a stubborn child. "Look, there's something seriously wrong with you. But listen, if you don't eat, your body won't have the nutrients to recover, and this training will be pointless."
"THEN I'LL EAT WHILE TRAINING!"
"What?"
"JUST CHUCK THE FOOD IN MY MOUTH WHILE I TRAIN!"
Kenzo stared at me, his expression a mix of disbelief and exhaustion. "Do you have no respect for food? Or for the divine beings above who blessed us with it?"
"ITADAKIMASU!" I roared, seamlessly shifting into my training katas. Then, with all the grace of a starving beast, I threw my head back, mouth wide open. "AAAAHHH—THWEH!"
A fist slammed into my jaw, snapping my mouth shut with a resounding clack.
Kenzo shook his head, cracking his knuckles. "Shut up and come eat."
Kenzo shook his head in exasperation, believing that I was just drunk in power and that eventually, my dedication to learn would be dulled by the coming days.
He muttered under his breath as he grabbed my leg and started dragging me toward the house. "Whenever I look at you, I remember why I don't take disciples anymore. It's a good thing Water Breathers are the calm ones. The others get enhancements that are a pain to deal with."
"Others?"
"...Oh"
"You're telling me...there's different effects for different breathing styles?"
"Oh no"
"Oh yes"