"You, go down the mountain."
Sakonji Urokodaki wore his tengu mask, his voice intentionally cold.
At his feet, the black-haired youth Shirakawa Sato was clutching his pant leg, his handsome face looking up with an expression full of misery.
"No, Master!!!" (╥﹏╥)
Shirakawa Sato drawled out his words, his eyes red. "Please don't leave me behind!"
"I am not your master." Sakonji broke free from Shirakawa and turned to leave.
"It's been eight months and you can't even grasp the basics of a Breathing Style. I've never had a disciple as talentless as you."
These words were a bit hurtful, but they were the truth.
For eight months, Shirakawa Sato couldn't even feel the 'Total Concentration' of Water Breathing. Every time he trained, he would choke on his breath and cough like a consumptive patient.
"But Master! I have rare blood! If I go down the mountain, I'll just be delivery food for demons—the top-tier sashimi platter kind! Do you have the heart for that?"
These words made Sakonji pause.
Indeed.
A rare blood constitution is an absolute feast for demons.
Especially since this kid's rare blood was the rarest of the rare.
Eating him alone would be equivalent to devouring at least a hundred people.
If he wasn't discovered, it would be fine, but if he was, no demon would ever let him go!
If this foolish boy really wandered down the mountain with such a constitution, he probably wouldn't last long.
"There's a village at the foot of the mountain; I'll find you a place to stay." Sakonji's tone softened slightly. "I'll come over if anything happens."
"But what if you're late? What if the demons launch a blitzkrieg? What if—"
"There are no 'what ifs'."
"There are, there are!"
Shirakawa Sato performed a textbook sliding kneel and grabbed Sakonji's left leg again, his movements so practiced it was almost pitiable.
"Master, please just let me follow you! I'll serve you tea, pour water, massage your back and legs, and I can even tell jokes! Once upon a time, there was a mountain, and on the mountain, there was a temple. In the temple, an old monk was listening to a young monk tell a story—"
"Shut up." Sakonji's temple throbbed. "In these eight months, you've broken three of my teacups and burnt the rice five times. Who's serving whom? Let go."
"I won't!"
"Let go!"
"I'm not letting go!"
...
In the sky, the setting sun dyed the clouds orange.
Sakonji stood there, his tengu mask facing into the distance, his entire being radiating an aura of "I'm so tired."
Shirakawa Sato squatted three meters behind him, chin resting on his hands, smiling broadly. If he had a tail, it would probably be wagging so fast it would blur.
Failed again.
In these eight months, the number of times Sakonji had tried to drive him away was astonishing.
But it couldn't compare to the thickness of Shirakawa Sato's skin, which was even more impressive.
Not once had he succeeded.
"I'm going to pick someone up," Sakonji spoke faintly, as if resigned to his fate.
"I'm going too!" (◕ᴗ◕✿)
"You are not allowed to go."
"Then I'll go secretly!"
The veins on Sakonji's forehead bulged instantly, forming a pound sign. Finally, unable to take it anymore, he took a deep breath.
Shirakawa Sato was all too familiar with this breath.
Every time Sakonji found him annoying and wanted some peace and quiet, he would take a deep breath and then vanish with a 'whoosh'.
Water Breathing: Technique of Slipping Away!
Sure enough, in the next second, Sakonji turned into a blue-black afterimage and dashed down the mountain path.
He ran away again!
"Master, you're doing this again!" [○･｀Д´･ ○]
Shirakawa Sato jumped up and took off in pursuit. "You can't shake me off—!!"
In eight months, he hadn't mastered a Breathing Style, but he had developed a solid physical condition.
Now, he could run a hundred meters in under nine seconds.
His long jump exceeded nine meters.
As an ordinary person who inexplicably transmigrated into this world with his original body, achieving this level of physical fitness exceeded his expectations.
It seemed that ever since he arrived in this world, an aura had been invisibly and slowly altering his constitution.
This was also why he was obsessed with Breathing Styles: I can do it! Even if I can't now, I definitely will in the future!
Of course, the main reason was... unwillingness to give up.
He had clearly transmigrated into his favorite anime world and even had his own system.
Yet, simply because he didn't know a Breathing Style, the system had remained stuck and unable to activate after granting him basic language skills.
To make matters worse, his blood turned out to be one of the rarest bloodlines in this world.
Setting aside the fact that he couldn't become an overpowered protagonist with a system, he couldn't even live as a normal, ordinary person.
Who could he even complain to?
By now, he had long since figured it out. In this land infested with demons, an ordinary person with rare blood like him had only two ways to survive without being eaten.
One was to become a "thigh," and the other was to cling tightly to a "thigh"!
Since he still couldn't learn a Breathing Style, he could forget about becoming powerful for now...
He could only, and must, cling to the thigh of the former Water Hashira of the Demon Slayer Corps, Sakonji Urokodaki.
Wherever you go, I go!
Never stay alone and become a meal for a demon!
Up ahead, Sakonji glanced back at his huffing and puffing "disciple," and a soft sigh escaped from beneath his mask.
In the end, he slowed his pace.
Meanwhile, several miles away... the woods were quite lively.
Tanjirou, the boy with the scar on his forehead, and his sister Nezuko, who had just turned into a demon, were fighting a demon.
Strictly speaking, it was two against one.
Although Nezuko was now a demon, she was helping her brother.
The Temple Demon was bewildered.
He had been a demon for years, and he had never seen a human and a demon beat up another demon together.
Even less had he seen a demon helping a human!
He was so angry his head fell off—literally. It was sent flying by a kick from Nezuko.
Unfortunately, when a demon fights a demon, no damage is taken.
Tanjirou didn't have a Nichirin blade in his hand either.
So even though the Temple Demon was split apart, he could still fight on two fronts with his head and body separated, leaving the two in a miserable state.
Fortunately, that demon head with hands growing from its neck was pinned to a tree by Tanjirou's axe.
The headless demon body was finally thrown off a cliff by the siblings in a narrow escape.
Now, Tanjirou held a dagger, standing before the demon head with hands, panting heavily, his hand trembling.
Killing a person... no, killing a demon, requires resolve.
Just as Tanjirou was giving himself a mental pep talk, a powerful hand silently pressed down on his shoulder.
Tanjirou was startled and stiffly turned his head, a fiery red tengu mask coming into view.
"You can't kill him with just that!"
From beneath the tengu mask, a low but reassuring sentence officially bound this fated master and disciple together.
If things followed the normal course, Tanjirou would next face his first demon-slaying test from Sakonji Urokodaki.
Everything would proceed according to this world's original trajectory.
But...
When Shirakawa Sato appeared on the steps, panting for breath, everything... changed...
Nezuko, who had been waiting obediently, suddenly twitched her small nose twice.
Her pink eyes suddenly shrank into cat-like vertical slits.
A scent so rich that her very soul craved it instantly overwhelmed her already fragile sanity!
In the next second, two threads of crystal-clear saliva trailed through the air, and Nezuko vanished from the spot.
"What the—"
Before Shirakawa Sato could finish speaking, he was tackled to the ground.
A petite but incredibly powerful body straddled his waist, her pink kimono brushing against his cheek.
Beneath the tengu mask, Sakonji's expression changed drastically.
"Oh no! He's a rare blood!"
Without hesitation, he turned and gave chase.
But would he make it in time...
Nezuko had already leaned down to bite, making Sakonji's heart sink halfway.
This little girl demon, who had been calm just moments ago, clearly couldn't resist the temptation of Shirakawa Sato's rare blood. At this moment, she had already buried her head into Shirakawa Sato's neck.
There's no choice! Blood has been drawn!! She cannot be allowed to live!!!
Just as Sakonji pulled out the Nichirin dagger he always kept at his lower back, preparing to finish Nezuko off—
Shirakawa Sato's handsome face peeked out from in front of Nezuko.
The moment he saw that face,
Sakonji's heart skipped a beat, and he froze as if struck by lightning.
What kind of expression was that?
Enjoyment? Satisfaction? Pure bliss???
You brat, you're being gnawed on by a demon! Why do you look like you're enjoying a midnight snack?
Also, where are your hands?
The demon is grabbing your shoulders, and it's one thing that you're not struggling, but why are you cupping the girl demon's butt!?
Fortunately, this little girl demon had a bamboo muzzle in her mouth. As she tried to bite, her mouth couldn't open, so it was more like she was nuzzling him.
No wonder... that kid had such a subtle expression.
Of course, these weren't the real reasons why Sakonji stopped.
Even if she couldn't bite, she was still a demon.
The flush of red on Shirakawa Sato's face was what truly surprised him.
This fiery red wasn't blood—at least, not blood spilled externally.
It was a flush radiating from within.
As a former Water Hashira, Sakonji's perception was extremely sharp.
He clearly "heard"—
Thump-thump! Thump-thump! Thump-thump!
Shirakawa Sato's heartbeat was as fast as a drum.
The sound of blood rushing was audible.
Accompanying it was a rise in body temperature.
Even more obvious was the breathing.
The previously chaotic gasping had, at some point, become deep, steady, and full of rhythm and power.
With every inhale, his chest visibly expanded.
With every exhale, there was a faint... pale pink airflow leaking from his mouth and nose.
Total Concentration Breathing?!
At this moment, Sakonji's grip on his blade loosened.
He remembered Shirakawa Sato's stubborn and determined eyes every time he practiced a Breathing Style over the past eight months.
This kid dreamed of learning a Breathing Style.
Now, the opportunity was right before him.
He couldn't interfere.
"Nezuko! Let go of him quickly!!!"
Realizing what was happening, Tanjirou finally reacted and shouted as he rushed over.
But Sakonji scooped him up, covered his mouth, and lifted him away.
"Mmph! Mmph-mmph!" Tanjirou's eyes widened, his limbs flailing.
"Be quiet," Sakonji whispered, his eyes fixed on the two tangled together on the ground. "Watch."
Tanjirou followed his gaze.
In the night, Shirakawa Sato lay on the grass with Nezuko on top of him.
The youth's eyes were closed, appearing to enjoy himself, while his breathing grew deeper and steadier.
As he breathed, the pink airflow leaking from his mouth and nose became more visible, like early spring cherry blossoms, gently wrapping around him and Nezuko.
"That's..." Tanjirou forgot to struggle.
Sakonji didn't speak, his lips pressed into a thin line beneath his mask.
That pink airflow... was definitely not one of the five basic Breathing Styles, nor did it resemble any known derivative!
It was somewhat similar to the Breathing Style of the current Love Hashira, Kanroji Mitsuri, yet not quite the same.
Sakonji couldn't help but mutter, "This kid actually created his own unique Breathing Style in a life-or-death moment!?"
Watching Shirakawa Sato's increasingly steady breathing,
Seeing Nezuko, who inhaled that pink aura, gradually relax and even begin unconsciously nuzzling his chin with her cheek...
Sakonji suddenly felt...
This troublesome kid he had picked up might actually be an incredible little monster.
On the ground, in Shirakawa Sato's mind, a mechanical voice was rapidly echoing:
[Host detected to have successfully mastered a Breathing Style!]
[Conditions met!]
[System adapting—adaptation complete!]
[System activating—activation complete!]
[Welcome to the Color Breathing Auxiliary System!]
Shirakawa Sato's tightly closed eyelids snapped open.
It's here.
His cheat... has finally... gone online! (≧∀≦)♪