A/N

This story is a crossover between the manga, Even if you slit my mouth & KNY. Knowledge of the former is not needed. And on a side note, all rights to these respective works are owned by Akari Kajimoto and Koyoharu Gotouge.

No one quite knew when the two first arrived in the city.

Simply, one day, they were there. A sweet elderly lady, and an exuberant young man. No one thought to question their presence. City goers, afterall, didn't have the time. Too ruffled and fixated on their affairs and state of dress. And so, just as the whispers of the street drifted by, they too did, swept away by the hustle and bustle of Tokyo. The city lights waning day by day, the clinking and pounding of footsteps overtaking, leaving but a wisp.

Akio knew the two just as well as anyone else, if not marginally more, as their neighbor.

He knew the woman was named Saya, however, her last name escaped him. The fact that it also escaped everyone else, only encouraged their local rumor mill, the gaggle of old women it made up awfully creative. He had long learned to not listen to them, after his wife had taken to glaring at them. Personally, he liked to think she simply preferred her given name, many folk did, after all.

Saya was a short woman, all small limbs and petite legs. Always donning the same kimono, a rather pretty one that, with its intricate patterns and violet accents. It was something his own grandmother would wear. Partnered with how she wore her hair, already silver with age, put up all traditional -Which only served to puzzle his nosy neighbors more. Since, why would such a proper woman lack a last name?

He didn't think much of her. Aside from the food she served at the eatery she ran being heavenly, there really wasn't anything special to her. Simply a lady getting up in her years, friendly too, pleasant. But that was expected, with her face full of smile lines.

The other one was a little more odd, but he just chalked that up to the youth being strange. The western nations were already affecting his home, changes and differences were commonplace. Especially in the city, where it seemed everyone was so eager to seek that brand of novelty.

Uda, was the young man's name. And just like Saya, he also lacked a last name. Looking like a foreigner with his bright locks, perhaps from France or some other light hair bearing country. He styled it in the most peculiar way, cut just so they obscured his eyes from view. His attire was less odd, simply a high cut shirt with a haori thrown over it with hakama pants, neutral in color. The boy, because he couldn't be more than twenty- he often saw milling around the eatery. Helping out with the foodstuffs. Nothing more than a cheery youth, if you ignored his hair. Now, hadn't those two been needing produce? He was a good man, and a better neighbor, he could get them some radishes.

Kaede liked Uda. Perhaps because he spoke a little funny, or because he had hair the color of straw. She didn't quite know, but it could have been the food. It was a hidden gem, a treasure sequestered, squirreled away in a tight corner. A place only locals knew about, a place only she knew about because her Grandpa liked going there a bit too much. Because beside all the heckling he made at the foreign man, she knew he liked him. She could see the twinkle in his eyes, the lax posture of his shoulders, yes, he did quite a bit.

Maybe it was how they smiled, how he never failed to greet them when they stepped through into their homey corner. All warm woods and smells, chairs squished together so that everyone ate with their elbows touching. Whatever the reason, she knew there would always be a place she could duck into from the rain. To stare at her school shoes, huddled up to strangers simply enjoying a warm meal.

The eatery was also special to her personally. See, she knew something no one else did. She knew a secret of theirs. From a young age, Kaede had always been sharp, a girl with a keen sight. So when she saw how Uda's teeth seemed to gleam in the light, too pointed. When she saw how the air sometimes rippled with something wholly other, how the metal snakes on the mantle seemed to slither, alive for all but a second. When Uda saw her stare, cheekily holding a finger to his lips in a playful hush, winking. She knew.

Kaede could keep a secret.

Sato didn't trust the lot. Couldn't. Not as far as he could throw them. He could smell it. Something was utterly wrong with the pair. He just for the life of him, failed to discern what. As someone who had been living in Asakusa his whole life, he just couldn't shake the itch he got, whenever he walked past that blasted eatery.

He just couldn't understand. One day, they were just there. One slow evening in the midst of summer, they had simply arrived. Suddenly and with no explanation. No one in the community knew them, no one had even heard of them, and the kicker was that no one cared. Welcoming them blindly, something he couldn't bring himself to do. That day was a few years ago now, but nevertheless, the feeling still gripped him. There was something wrong, if only he could figure out what that something was. It was driving him mad.

Mad, yes, that was what he was. Afterall, only a mad fool would be currently eating food made from such unsavory people. Clenching wooden chopsticks in a white knuckled grip, he could only wonder how he had gotten in this scenario. Sitting hunched over, delighting in a bowl of food that brought him back to his childhood. To grassy fields and bright skies, to nights lit up by the stars instead of by electricity. He couldn't believe himself, truly. Yet despite his swirling feelings of apprehension, it was probably the best darned meal he had in a while. Something even he could grudgingly admit. So perhaps he could make an exception, if only this one time. Or maybe two times, or…

Sato didn't trust them, but he could appreciate good food, and damn him, if he would.

Somewhere sequestered, squirreled away from view, is an eatery. A place only the locals of Asakusa know about. All wooden walls, imperfectly built. Two fabric flaps guarding the entryway, dark blue and fluttering in a wind that isn't there.

No one quite knows when it was established, or when the pair who ran it first came to Asakusa. No one even knows the name of it. As if it was carried away by a breeze, floating, drifting, too far to grasp.

.

.

.

*Ding!*

A rustle of fabric and the shuffle of feet is heard, revealing a young man with burgundy hair. A tired expression on his face, a young girl trailing behind.

"Pardon me sir.. Could I get a bowl of udon with grated yam?"

"Of course, of course! Just wait right here!"

Uda chirps, disappearing into the back.

It was around three years ago, when Tamayo first felt it. Reverberating like a broken cord, echoing distantly. The feeling of displacement, of something that should not be. It was three years ago, when she looked up to the darkening sky, before turning back to her work, deeming it inconsequential. The memory now of that night is hazy, forgotten and replaced by much more important things, things of potential.

Now, she's unsure.

The city was so overwhelming. Too bright, too loud, too pungent, too many people, the buildings too tall. Everything was too much, so much so his head spun, dizzy. All Tanjiro could do was weakly try to find a place of reprieve, dragging a sleepy Nezuko behind him. In what felt like hours of searching, accidentally stumbling upon a pair of lovers in the process. After a hastily spoken apology and darting out the alley, they had finally found a stretch of road a smidgeon calmer.

Their shadows flickering from the street lamps, it was then Tanjiro found it. Nuzzled by the wall, what looked to be an eatery stood in all its worn glory. Elated but too frazzled to express it, he sent a silent word of thanks before entering, the ringing of a bell following him.

After ordering, he was quickly welcomed. The voice coming from a young man with blond hair. A wide grin on his face and a slight twang in his voice. He was taller than him by a fair margin, bobbing his head before heading to the back.

Relieved at the prospect of finally being able to just rest, he glanced at Nezuko. She sat by him, the sleeve of her kimono brushing his side, leaning on his shoulder. He couldn't help smiling, happy to just be with her. A wave of love and protectiveness washed over him, softening his gaze. He would keep her safe and turn her back, whatever it took. His quiet reverie was quickly broken however, by the reappearance of the man.

"Aw, you two are sweet, huh? Close with your sister, kid?"

Quickly recovering, Tanjiro directed his attention to the man, still smiling.

"Always, she's the best."

Leaning slightly on one foot, the man's grin softens as well.

"That's good. I have a soft spot for kids like you, Tanjiro, here's your udon. On the house."

Slightly flustered, he accepts the bowl gratefully. Inclining his head in a quick bow.

"Thank you!"

"You're welcome."

Warm, Tanjiro turns back, gazing into the bowl in his hands. He can smell it, divine and homey. The broth glinted and sparkled beautifully. Whoever made this clearly put a lot of care into it, the thought further warming his heart. Bringing it to his face and taking a sip, the soup is absolutely delicious. Savoring the moment of calm, at ease and safe, finally content after encountering that wreck on his senses.

It doesn't last long.

For soon after, the smell of blood invades his nostrils. Overpowering everything else, spreading its disgusting pungency. Causing him to carelessly drop the bowl with a harsh *Clank!*

He makes his way to the city center once again, calm all but forgotten, fire in his veins. In his rush, he doesn't even think to question how the man had known his name, despite not giving him his. If he did, perhaps he would've also noticed how the air had curved around the man, or how through the hair that covered his face, his eyes glinted, pupils like a snake and dripping gold. Or perhaps most of all, the underlying scent of something ancient and powerful that permeated every surface.

But Tanjiro didn't, so he noticed nothing.

Miffed, Yushiro stared down at the siblings. His eyebrows scrunching together, irked. Standing by a tree with his hands to his sides, he couldn't see what Lady Tamayo saw in them. But, it would be a crime to doubt, so here he was.

"I'm here on Her orders, i'm supposed to bring you back with me."

He stated, looking at the boy's face, already annoyed with him. Tingling on his senses though, was something he couldn't quite place. Something heavy and oppressive, it coated the area. Thick like a blanket, practically suffocating him in its aura. Something had taken up residence here, something ancient and cold. And he had encroached on its territory. It instantly put him on guard, clenching his fists, only half paying attention to what the boy was saying. Absently replying to his foolish question.

"Our hiding place is protected by a concealment spell, you never would've found it."

The boy simply stared back, uttering the word again like a brainless parrot.

"Concealment?"

He sighed, looking the pair up and down, before settling his eyes on the girl, narrowing them. Something about her...how strange. Lifting a finger, he pointed at them before speaking.

"Before we go, did you know that girl is a demon?"

Looking at her closer, he added deliberately.

-and not much to look at."

Tuning out the boy's indignant shouting, he strained his senses, checking the area once more before beginning to lead the pair to the house. Looking around, only slightly panicked, trying to see if anything was amiss. After his scrying, he felt a breath he didn't know he was holding come out. It seemed whatever had left its mark here wasn't planning on keeping them there. For a second, he could've sworn it would. Having felt a sickening feeling of certainty mere seconds before. As if a gaze was ripping into his back, promising things best left unsaid. That if they hadn't started leaving when they had, they wouldn't have been as lucky. Gulping slightly, a bead of sweat sliding down his neck, he resolved to keep walking. Not daring to look back.

Anyhow, Lady Tamayo would know what to do. She would.

"So, what do you think, are these requests acceptable, if not pleasant?

Sitting in that room, his knees brushing against tatami, he felt his resolve harden. At last, Tanjiro had a path to follow, a glimpse at hope. Ms. Tamayo had told him she could make a cure, then he was going to help wholeheartedly. Glancing back at Nezuko sprawled beside him, her hand in his, there really was no question in the matter. Looking at his sister, he felt his heart get tied up in strings. Even if it took years, decades, he would happily cut down as many demons as he had to, if it meant a cure. He would travel to all four corners of the country, of the world, if it meant he could even help in the smallest way- he would do it. Wouldn't even bat an eye.

He thought about this carefully, before answering.

"If it's really the only way, I'll do it. Besides, if you research all that blood, and you can create this medicine, it won't just be Nezuko, will it?"

Turning back to face her wholly, he smiled as he spoke.

"A whole lot of people will be saved too."

He watched as a sweet smile painted itself on Ms. Tamayo's face. Her eyes twinkled pleasantly.

"Yes, it will."

The moment was broken, however, by the chime of a bell, and the whoosh of something cutting the air.

And in a blink, everything changed.

It had happened so fast, the events still had Tamayo reeling. One moment, they were facing a pair of demons, the second, she was looking at the back of a man with blond locks and a cheshire grin. His features seemed to twist just so, just so they felt unnatural. Deeply wrong, something about his grin being too wide, and his skin too pale, his body too long. And then, before she even had the chance to breathe, he opened his eyes.

Tanjiro smelled the man before he heard him, before he saw him. The distinct smell of spices and the sun kissed scales of a snake. Of honey suckles covered in a tinge of bitterness, a poison. Of something faintly familiar, like a warm bowl of udon. Udon…

That man! He knew that man. It was the kindly shop owner, and he was currently standing in front of them. Lazily facing the two demons with a dismissive air.

A cold shot through him, freezing his veins. Tanjiro didn't know how he had gotten here, but he was going to die! He couldn't let that happen, he refused!

The same voice he remembered elected that moment to speak, it was in an easy drawl, as if he was still simply asking him what he wanted to order.

"Now, now, whatcha think you two are doing? Playin' catch?"

The demon with the temari laughed in a sick, breathless way, before quickly quipping back, a snarl on her lips.

"Die!"

Sending her temari to fly in a deadly arch, eagerly awaiting the moment they tore through the newcomers head. Crushing bone and spreading brain matter into pink mist, eyes combusting on impact.

But that moment never came.

Just a mere inch away from his face, the man went to uncover his eyes, grinning all the while.

"Dear, I'd rather not."

As soon as those words were uttered, as they rolled off a tongue hidden behind pointed teeth, a dark mist coalesced the area. Dripping off the man's body in waves, slick like oil spill. In a chain reaction, the demon's weapons fell slack to the ground, their bodies following shortly. A dull thud echoing in the area, silencing the air with a harsh finality.

Looking closer, in shock, Tanjiro could see that they had been petrified. Frozen in time, cursed to don a terrified scowl, eyes widened in horror. The face of someone facing death.

The soft crunches of footsteps wrestled Tanjiro's eyes from the statues, to see the man looming over his creations. Tanjiro could only watch silently, as he lifted a polished shoe over them, ruthlessly stomping down, shattering their petrified form. A light chuckle erupted from the man's throat as he did so.

After this, he cocked his head to the side in an angle no human could possibly replicate, the man, no, the creature speaking to him for the first time.

"Why, I don't think you finished your meal. Seems I owe you another! So, when' ya free? I sorta have to help my wife out with dinner, so maybe tomorrow?"

All Tanjiro could do was stare.

A/N

Born from my recent obsession with Uda, alongside my fervent love of crossovers. Will likely remain a oneshot, but I am intrigued by the idea of this being a full length story. With that aside,

Thank you for reading!