Rengoku Mansion.
It's been days since Kotaro and Mitsuri arrived at Kyojuro's place, and one thing has become more apparent as time passes.
"Damn! It's hell!"
Kotaro was drenched in sweat as he dragged himself to keep running. Though he had been exercising for about a month, he was still a novice. His body lacked the basic fitness needed to fight demons.
As soon as he arrived, he was told to run as much as he could, with Kyojuro guiding him, holding a wooden sword, and urging him to run faster.
"Run, run faster, Kotaro!"
"W-Wait! I can't breathe---"
"Push yourself to the limits! Surpass yourself, Kotaro!"
Damn! Those words aren't motivating me! Kotaro gasped for air, trying to keep running on wobbly legs. But soon…
'My head…'
"Shit! I'm blanking out---"
With a thud, Kotaro Kenshin, only a few days into his stay at the Rengoku Mansion, collapsed from exhaustion.
...
"Ack! This pain…!"
Kotaro woke up with a splitting headache, holding his head as he opened his eyes, finding himself in an unfamiliar room.
"Where am I? What was I…?"
!!!
Then Kotaro remembered everything—how he had blanked out from exhaustion. He couldn't believe he had passed out from over-exercising. To think such a thing had happened… Anyway, Kotaro was somewhat prepared for this.
He was trying to become a demon slayer, so an exorbitant amount of exercise was necessary to grow strong enough to fight and survive against demons in the future.
But he never expected it to be this intense!
"Kyojuro…"
Then he realized he had overlooked one thing. He had come to none other than Rengoku Kyojuro for training, the man who trained so enthusiastically that people fled from becoming his Tsuguko.
"Am I screwed?"
And then…
"Kotaro, you're awake! Let's practice!"
"You must be kidding me!"
...
Days turned into weeks, and weeks into months. Two months had passed since Kotaro first arrived at the Rengoku Mansion.
"This sweat…"
In a swift move, he disrobed his training clothes and squeezed them, filling the bucket with sweat. This had become part of his daily routine. His body, which had been more like that of an average person with a bit of fat, was now transformed into that of a warrior. There were sharp lines and explosive muscles, making him a bit bulkier than before.
This was the result of hellish training. It's a miracle he's still alive at this point.
"I should take a bath."
Today's training session was over. Kotaro walked to the bathroom, cleaned himself up, and headed toward the dojo, where the sounds of swords clashing echoed.
"More! You can do more, Mitsuri! A thousand more!"
"I want to take a break… My tummy hurts. I'm hungry~"
"But we had lunch a while ago! You only have a thousand more, Mitsuri!"
Mitsuri whined while sparring with Kyojuro, who showed no signs of relenting. Kotaro watched them and smiled, finding relief from his own pain as he witnessed Mitsuri's struggles.
Unlike him, who had a poor physique, Mitsuri didn't have a problem with that. She had completed the basic fitness training much faster and had already transitioned to combat training, which consisted of regular spars with Kyojuro.
"Kotaro-sama~"
She turned toward him with teary eyes, but Kotaro just averted his gaze. Didn't Mitsuri want to become stronger? She has to work harder, and he, as her husband, has to support that!
Kotaro gave her a thumbs up and quickly walked away, fearing that Kyojuro might ask him to join the sparring, ruining his small bit of rest time.
Still, he meant it. As much as he disliked this hellish training, it was effective. His strength, stamina, and speed had all improved. Unlike when he trained by himself, the training under Kyojuro's guidance was much better.
Since Kyojuro had been trained from a young age, he understood the core principles and could guide better. And for Mitsuri, this was crucial, as wielding a sword couldn't be mastered instantly. As a demon slayer, she would eventually wield a sword, so it was better to get used to it.
As for Kotaro…
"What weapon suits me?"
It was a question that needed to be answered. Kotaro was destined to walk a different path than a typical demon slayer. He needed to find a weapon that would best harness his unique power—Hamon.
A sword could work, but it didn't bring out the best in Hamon. It lacked versatility, which was opposite to the nature of Hamon. Moreover, he didn't want to use a weapon that everyone else used.
"A chain might be good."
A long chain with some weight at the end might be the best option. It's cool too. But wielding it would be a pain. Plus, it could be useful for long-range attacks, but for short-range…
"Hmm… Maybe I could use something like nunchaku. But still, that would be too short… Wait! Maybe I could use that—Playful Cloud."
Unlike nunchaku, Playful Cloud had three bars connected by chains. The reach could be much longer than a regular nunchaku, and most importantly... it hits harder!
If he used Hamon on it and struck a demon… Just thinking about it gave him shivers.
But it was still just a thought. Kotaro decided not to think too much about it and let his future self figure out if he could wield it. For now, it was time to focus on the fundamentals.
Up to this point, he had been training his body, but now it was time to train the power unique to him—Hamon.
And for that, he decided to ask Kyojuro to teach him the next step of Breath Style.
Total Concentration Breathing: Constant.
===
A/N:
Thanks for all your suggestions! Hamon certainly strengthens human traits, though not as explosive as the Breath Style, but it still does.
And the new arc - [Kotaro Kenshin, The Demon Slayer] begins!
Breath Style and Hamon both rely on controlled breathing. This means that the fundamental way to strengthen these techniques is to improve breathing itself. Kotaro remembered that in JoJo's Bizarre Adventure, Lisa Lisa trained Joseph and Caesar using a special modified mask that only allowed breathing if done correctly; otherwise, the mask would suffocate the user.
In essence, this training was quite similar to that used for Breath Style—specifically, Total Concentration Breathing: Constant. As the name suggests, this involves using Total Concentration Breathing all the time: during the day, at night, and even while sleeping. The difference between those who can use it and those who cannot is vast. And Kotaro intended to learn it.
To produce Hamon, he had to take a huge breath in one go, but after successfully learning the Constant state, he would be able to produce Hamon whenever he wished without needing such loud, deep breaths.
"Indeed, I want to learn this constant state. But…"
Pant! Pant!
"Why the hell am I still running?!"
"Running helps to improve lung capacity with fast movements. That's why, Kotaro, run faster! I believe you can do it!"
Kotaro looked at Kyojuro, who was running behind him with a smile that scared him more than anything. Damn! This is why no one wants to become his Tsuguko.
Bang!
"Why did you hit me?!"
"Kotaro, your breathing is disordered. Even while running, maintain that Hamon breathing! That's how you can learn the constant state. As promised, I will do my best to teach you! Let's go!"
As easy as it sounded, it wasn't at all. It was quite hard for Kotaro to maintain the constant Hamon breathing state. A bit of exhaustion, and his breathing became disordered.
But he was still managing it. Unlike normal Breathing Styles, Hamon also had medicinal uses. Kyojuro's eyes sparkled when he learned about it.
"That's great news. Kotaro, you can truly surpass your limits!"
And then he made the training even harder. If Kotaro complained of pain—heal it with Hamon.
As hellish as it was, the effects were also apparent. Kotaro could feel his overall abilities increasing dramatically. His body was adapting to Hamon more due to constant use, and he was becoming more proficient in using it.
Originally, he thought that Hamon could only generate the sun's energy, but he realized it also had the same effects as Breath Style—it enhanced the body's physical traits.
"I was mistaken. If Hamon couldn't strengthen physical aspects, then how could Jonathan and Joseph fight those monsters?"
Vampires and Pillar Men are monsters that exceed human capabilities. If Hamon only generated the sun's energy but didn't strengthen physical traits, then humans wouldn't have been able to fight those monsters in the first place.
Kotaro's memories of JoJo were fading a bit, but he still remembered certain iconic moments that showcased the physical strength gained from Hamon training.
The Sitting Jump—Kotaro still remembered it. Baron Zeppeli demonstrated it to Jonathan when he first visited him. How could a normal human jump so high while sitting cross-legged? Moreover, if he wasn't wrong, there was also a scene where a Hamon fighter created afterimages with his speed while fighting Dio.
Still, it was manageable with vampires. But when it came to the Pillar Men, it would be impossible to fight them if physical traits weren't enhanced by Hamon. Those guys were true monsters, possessing superhuman strength, toughness, speed, senses, and even intelligence.
"Hmm… I have to remember more details about Hamon."
While his power being much more powerful than Breath Style was an advantage, the fact that no one else used it made it harder for anyone to teach him about it.
Kotaro could only rely on his memories from his previous life to learn and master Hamon. So, every night before he went to sleep, he tried to meditate to improve his concentration and used this time to remember all the details he could about Hamon and write them down in a simple notebook.
"The smaller the area of contact, the stronger the Hamon is transmitted…"
All points, all moves, everything related to Hamon that he could recall from his memories, he noted them down so he wouldn't forget later.
For now, he was still training to learn the Constant state. But…
"Ack! Damn, who… Senjuro!"
Kyojuro's younger brother, Rengoku Senjuro, stood there with a wooden stick, looking at him with apologetic eyes.
"Sorry, Kotaro-san, but Ani-ue told me to…"
Damn! All that torture during the day and even now in his sleep… But Kotaro couldn't blame Senjuro, this kind-hearted boy, for that hellish Kyojuro.
Did both of them really come from the same mother? How can they be so different?! Kotaro was determined that once he became a demon slayer, he would never return to this place. Now, he had to sleep to prepare for the training tomorrow.
"Zzz… Ack! Damn, no!"
The stick fell on him again, and Kotaro woke up just as he was about to fall asleep because of Senjuro.
"Sorry, Kotaro-san."
'Don't say sorry, just spare me!'
Now tears were starting to form in his eyes. Did he really go through all of this to become a demon slayer? Why did he want to become one?
'Mitsuri! I will not spare you!'
Kotaro decided to punish Mitsuri for all his suffering some unknown night by making her cry all night. But that was a matter for the distant future.
For now…
"Ack!"
All Kotaro prayed for was a good night's sleep.
===
A/N:
Really, nothing in this world is better than sleeping.