My Cute Wife is Mitsuri Kanroji

"Thank you, Kotaro," Kyojuro said sincerely as he patted his little brother, who had fallen asleep after crying so much. Kyojuro was always lively, but he wasn't a fool. He was highly perceptive of emotions and understood the world around him deeply.

For a long time, he had been worried about his brother, who seemed to be trying to live up to the expectations of their father and Kyojuro himself, wanting to become a demon slayer to succeed them but unable to do so.

Kyojuro had spoken to him many times, reassuring him that as long as he became a good human being, he could help others in different ways. Still, somewhere deep inside, Senjuro was stuck, unable to move past his perceived lack of talent.

Today, Kotaro's words had likely helped Senjuro take a step forward, and for that, Kyojuro was truly grateful.

"No need to mention it. I also think of Senjuro as my little brother."

"Is that so? But still, I can't let this be a one-sided favour."

"Well, if you really want to repay me, then—"

"I'll train you more and make you a qualified demon slayer!"

"Please, don't! Seriously."

…

A new morning. 

The man who used to wake up after the sun now ran outside, drenched in sweat before it had even risen.

Time changes men. 

But today's run was different from Kotaro's usual routine. His breathing was much steadier than it had been months before. His efforts to master Constant Breathing were starting to pay off.

Sparks!

But the difference wasn't just in his breath, but in the sparks generated as he ran.

Constant Breathing is a method to increase lung capacity, which in turn boosts the strength of Hamon. But Kotaro had yet to master the techniques that accompanied Hamon. In simpler terms, his Hamon was strong, but his ability to use it was still crude.

To improve his mastery, Kotaro had started using Hamon during his runs. Now, he was generating Hamon and focusing it in his legs—or rather, in his toes—using one of Hamon's properties: Repel.

Hamon was truly an amazing technique. Not only could it heal, but it could also destroy the undead, pass through objects, be stored in conductive materials, and act as both an attractive and repellent force.

Kotaro was now attempting to use the repellent force in his toes, pushing off the ground to increase his speed. The smaller the contact area, the more Hamon would be transmitted. Kotaro remembered that tidbit and concentrated the Hamon into his toes rather than his entire foot.

Small sparks were visible on his toes, and upon contact, faint golden ripples formed whenever his Hamon-infused toes touched the ground. 

"It's more difficult than I thought!" 

Maintaining control to keep the Hamon concentrated in his toes while using its repellent properties to push off the ground…

Multitasking wasn't easy, but it was possible. And that realization lit up Kotaro's face. 

"This technique… I'll call it [Ripple Steps]."

Since small golden ripples formed with each step, Kotaro decided to name it [Ripple Steps]! High on excitement from naming this new move, Kotaro ran with even more enthusiasm, appearing as nothing more than a fleeting blur to the animals in his path, scaring them out of their wits.

"Ha~ Ha~ I ran too much!" Kotaro panted, feeling slightly drained, but his smile didn't fade. The process of experimenting and making new discoveries—it was addictive! 

"Ouch! This sharp pain… it's my nail."

Kotaro sat down and examined his broken nail, blood trickling from it—a result of pushing his body beyond its limits. He carefully removed the broken nail and decided to test his healing power. 

"Let's see how fast it heals."

Sparks started to form over his toes in a second, and soon Kotaro felt warmth. When Hamon is concentrated too much in a single spot, it can even generate heat, enough to start a fire. Fortunately, his toes weren't ablaze. 

"Oh! It's healed!"

It took less than ten seconds. His toes were perfectly healed, not even a scratch remaining. His broken nail had regrown, looking flawless.

"This healing power… I was still underestimating Hamon."

Since his Hamon hadn't worked to heal Aiko, Kotaro had subconsciously doubted its healing abilities. Aiko's injury had simply been too severe, making it beyond Hamon's healing capacity. But for minor injuries like this?

As long as he didn't sustain life-threatening injuries—like having his arms or legs chopped off or suffering a hole in his stomach—Kotaro believed he could heal himself. He needed to control this healing ability and use it more subconsciously so he could fight without worrying about his injuries. 

"Hmm?"

Killing demons with a single punch… No matter the injuries, they all heal… Using Playful Cloud to hit demons even harder…

"Am I becoming too scary?"

Kotaro knew Hamon was a remarkable power, but he hadn't realized it was this overpowered. 

"I should practice more."

He then started practicing classic Hamon techniques like Zoom Punch. All morning, Kotaro continued to use Hamon, multitasking different techniques. Sometimes he succeeded, and sometimes he didn't. The progress, however small, brought immense satisfaction, making the once training-averse Kotaro want to train even more. But in the back of his mind, he was still thinking about something else.

"While Hamon is great, I still have to attain that state."

The state he referred to was the zenith reached in physical combat, the Selfless State. In "The Demon Slayer", all three elements—Breath Styles, physical combat, and Nichirin Blades—have a zenith state, which can be attained when they reach the highest level.

The zenith of Total Concentration Breathing results in the Demon Slayer Mark, which exchanges vitality for enhanced power and grants access to the Transparent World.

However, since Kotaro was using Hamon, it was impossible for him to attain that. Hamon was different from Breath Styles, so it was impossible for Kotaro to awaken the Demon Slayer Mark or access the Transparent World.

He had given up on that from the start, instead experimenting with alternatives. However, this did not mean he couldn't attain the Selfless State, which could be reached by achieving the zenith of physical combat.

This state didn't necessarily enhance combat power, but it granted an unshakable calmness like a plant, allowing one to remain composed even in perilous situations and act without hesitation.

But it couldn't be achieved through practice alone; real-life combat experience was needed. 

"Sigh. This, too, is difficult."

For now, the easiest goal was to master a Red Nichirin Blade, which turns a normal Nichirin blade's colour into an intense red and can slow down a demon's regeneration. But… 

"Do I need it?"

Even Kotaro's casual strike, without a Nichirin Blade, could not just slow down but completely stop a demon's regeneration. Now, reflecting on all of this and looking at his Hamon, Kotaro realized his Hamon was far more powerful than he had ever imagined.

===

A/N:

Do you have ideas about some new, original moves using Hamon?