Demon Slayer: Muzan, will you dance too?

"I've mastered the breathing technique."

"Breathing Technique LV1→LV2"

A cold and emotionless electronic voice then began to play.

This time, no reward for a comeback was mentioned. Obviously, breathing techniques are not popular in the ninja world, so they were not recognized by the system and were classified as taijutsu.

It wasn't that Kiyokawa Izumi was after the so-called reward.

The vast majority of rewards given by the idiot system are useless—though they might be of some value if the concept of chakra were not involved.

Returning to the breathing technique itself, Kiyokawa Izumi didn't think too much about it at the time, just doing whatever felt comfortable.

While keeping the general direction unchanged, and referencing various breathing methods, one can create their own unique breathing method.

It wasn't exactly a stroke of genius; it was just so-so.

Yoriichi Tsugikuni could create the Sun Breathing technique out of thin air. Although the first generation of learners could not learn the Sun Breathing technique, they could create the five derivative breathing techniques under Yoriichi Tsugikuni's guidance, based on its principles.

Compared to these people, Kiyokawa Izumi, who possesses the Sharingan and is familiar with multiple breathing techniques, only created his own breathing technique when he had nowhere else to retreat—in comparison, he is clearly much inferior.

"It still lacks extreme explosiveness and speed, and compared to the steady, balanced, and offensively and defensive Water Breathing technique, it leans more towards concealing its own aura."

And, the use of the five senses!

Perhaps it could be called the Breath of Darkness.

Kiyokawa Izumi felt that this rudimentary breathing technique still had room for improvement.

Of course, because it suits me extremely well, it has a significant effect on improving my own abilities.

If the improvement in overall physical fitness is 1.5 times when using water breathing, then it may be 2.2 times, or even 2.5 times, when using dark breathing.

This data is obviously inaccurate; it was fabricated by Kiyokawa Izumi for ease of understanding.

Fu Nue felt that his speed had suddenly increased, probably due to the reasons mentioned above.

As for the blade suddenly disappearing?

It might be due to the sudden color change of the Nichirin sword.

The original blue has turned into a very inconspicuous dark silver.

And just then, the moon was obscured by clouds, making the blade appear as if it were hidden in the darkness, thus achieving the effect of invisibility.

"Let's call the first move 'Night Raven's Shadow.'"

As her consciousness gradually faded, Kiyokawa Izumi completely lost consciousness.

He was mainly able to hold on a little longer because he could hear human footsteps approaching.

Kiyokawa Izumi's kasugata crows disappeared after the battle began.

Just then, it was chirping anxiously when a burly, honest-looking swordsman strode over from not far away.

Upon seeing the signs of battle, Kentaro Tanaka swallowed hard, clearly taken aback.

He was also an experienced demon-slaying swordsman.

Based on a simple assessment of the traces at the scene, one can conclude that the evil spirit was extremely powerful.

He is probably no match for him.

Upon seeing a figure lying not far away, the kind-hearted senior rushed forward to check on it, and after a moment, he gasped in shock.

He doesn't know how to treat wounds in an emergency.

In previous battles, I have never suffered such serious injuries, nor have I ever encountered a demon who has mastered blood demon magic!

Seeing the burns on Kiyokawa Izumi's chest, I didn't know what to do for a while.

The hidden members should still be on their way—can the hidden members, who are in charge of logistics, really handle this kind of injury?

Feeling a chill run down his spine, Kentaro Tanaka knew neither how to treat the wound nor dared to touch Izumi Kiyokawa's body. He could only draw his Nichirin Blade and stand guard to the side.

……

The familiar ceiling, the familiar hospital bed.

"Isn't this the Wisteria family's house?"

Kiyokawa Izumi, whose eyes were throbbing slightly, murmured to herself in a daze.

I thought I would be taken by the hidden members to a place with the wisteria crest—this is not some strange organization, but just a family.

Having been saved by a demon-slaying swordsman, I am willing to provide them with free assistance, including food, lodging, and a doctor.

Kiyokawa Izumi was well aware of her injuries; the Hidden Members certainly couldn't handle them, and she needed a professional doctor.

Unexpectedly, after all the twists and turns, I've returned to the Butterfly Mansion.

The key point is, we haven't spent all the money yet!

Good afternoon, Mr. Kiyokawa Izumi.

A gentle voice sounded from the side, and Kiyokawa Izumi subconsciously turned her head to look, only to see that familiar smile again.

"My injury shouldn't be too serious, right?"

"This is serious. Did you encounter a powerful demon? Was it a Lower Moon?"

Shinobu Kocho spoke with a blank expression and a slightly serious tone.

"You mean it's a bit of a hassle, but not a big problem, right?"

Kiyokawa Izumi immediately realized that this person was teasing him. He gently touched his sore and itchy chest, mainly worried about whether he would get infected.

The concept of bacteria may have existed in this era, but antibiotics did not exist—penicillin was not discovered until 1928.

On second thought, perhaps there's no need to worry too much?

Both have breathing techniques that are almost mystical, and Shinobu Kocho's medical skills are far superior to those of ordinary doctors, so she should be able to handle burns that are not particularly severe.

"As for demons... if they really are Lower Moon demons, then don't expect me to be alive to pay back the money."