Not very often they see someone wandering in the back of her Mansion, a man, he looks out of place but with Kocho's reassurances, they don't ponder much on it, at least until the man makes himself present at a meeting.

A/N: Big shoutout to DJKPHOP for brainstorming this with me. Go give them a follow and thanks!

-linebreak-

Shinobu remembers it like yesterday when it happened. It was half a year into her time of being hashira, newly appointed, and still a bit of a fresh face when it came to these meetings. 

She knew most of them, she's had experience in caring for them on multiple occasions, and one of them would actually be responsible for how she met her mansion's physician- her- assistant and now partner, Tomioka Giyuu; Shinobu met said man through Sabito, the local Water Hashira. Giyuu, who was unable to slay demons due to an injury he acquired, due to a background in prior medical knowledge had taken to be the man's personal, traveling medic. Not that that was a bad thing, he needed it desperately. 

And so they met, they bonded over their shared work in medicine, and soon found themselves in a relationship. With Oyakata-sama's permission, despite not being a trained member of the corps, he became a part of it, the medical side at least. With the medical knowledge of old and more recent medical techniques used in the normal world- the one, she classified as such due to no one knowing or knowing very little of the existence of demons- could be helpful in advancing the medical techniques they use today.

Also, having someone skilled enough- in some fields not all, he wasn't as social as his friend was nor her- to hold down the fort while she was away on missions. Aoi and the other girls were skilled enough to handle it if they needed to, but an extra hand never hurt anyone. In essence, the current water hashira is responsible for the two coming in contact and also the only one aware of the following information out of all the hashira. 

She's not sure how it happened, but they barely ever crossed paths with him, only saw him in the background of the mansion, and whenever they asked she brushed it off, focusing back on what she was before. So no one knows about him, no one knows of him by accident, after all, she wasn't sure how to introduce him to any of the pillars. It's not like she could go up to them and say 'Hey, here's my physician assistant and my boyfriend, sorry I haven't told you about him despite the fact I've been dating him for years now. Anyway, how's your day going?' yeah exactly.

So she was currently thinking about a way to go around introducing them, maybe a double date with Uzui or Kanroji or Iguro, cooking with Rengoku, sharing tea with Shinazugawa, watching the koi pond or clouds with Tokito, and maybe meditating with Himejima. Too bad she didn't get to choose any of those options because he had chosen for her. 

It was a hashira meeting it took place at, it was a sunny day, half a year into her working at Corps as the newly appointed Insect Hashira when it happened. 

"Please, wait!" A voice had suddenly exclaimed as the meeting had just begun. Looks of shock reflected across the faces of the present pillar as they turned towards the left path.

There stood a man, poised, stood straight, and tall, shoulders back with his hands clasped in front, and a stoical expression, yet in the depths of their eyes was a small flickering flame of determination hidden away. The man's hair was inky locks, spikey bangs curved off to the right side of his face, his hair was pulled back into a loose ponytail that was spiked out from behind his neck, there was a voluminous amount of it that it seemed to be longer than it first appeared. His eyes were a dark blue, like the sea at night.

He wore a dark blue yukata with a pastel blue wave pattern on it and a juban, a red haori covering most of it, his pants were an ash gray colored umanori-styled hakama, and underneath it were white tabi's paired with plain zori's. He didn't look like a kakushi or a member of the Corps., but instead a regular person- that's a lie, the patterned yukata looked expensive. Everyone else just grew more confused than before, who was this random stranger impeding their meeting and why was he holding a letter in his hands? 

"What a daring and flashy way to introduce yourself! Interrupting a Hashira's meeting, it takes guts to do that!" Uzui broadly proclaimed as he clenched a raised fist as he stared at the man, eyes shining. "And wearing such a flashy yukata too!"

"Who the hell are you?!" Shinzaugawa snarled, glaring at the man.

"I ask you can bring yourself to forgive me for intruding on this meeting of yours, Oyakata-sama." To display both his respect and deepest condolences, one knee at a time, he kneeled seiza style and bowed deeply, head still hung low even after he was done, staying kneeled. "Giyuu Tomioka, partner and physician assistant to the Insect Hashira."

"Yes, I'm aware of your position Giyuu, and I understand the unfamiliarity of these proceedings. But I must inquire, what made you ingress on this meeting?"

"I thought we understood well that those not in the Corps., we're not to be made present of our existence and even then not to interrupt meetings." Iguro plainly stated, glaring at the man as his snake hissed in agreement. "Rules state unless put on trial those not summoned to the meeting shall not be present at it otherwise!"

"Yes, I fully understand but I only ask for a few minutes of your master's time, it's concerning a matter of utmost importance." His eyes briefly flicker up to stare at their master then they look down at the ground, lips briefly quavering before pressing themselves back into a thin line.

"You're far too late, this meeting has already started." Iguro continued to condemn, an aura of rage fizzing around him like a thickly veiled cloud. 

"A few minutes, I see no harm in it. Follow us please, we shall hold this parley inside." The corner of Giyuu's lips briefly twitch before they settle back into a line, and he bows. "Thank you Oyakata-sama, my dearest apologize for interrupting the meeting like this."

"Any partner or friend to a member of the Corps., is a friend to me." Tomioka stood tall and with careful steps, discarding his zori's beforehand, stepping onto the veranda, then turning towards the pillars and bowed, followed their master as he turned and walked into further parts of the mansion. 

"The meeting will resume shortly,"

"The meeting will resume shortly," The two girls echo, briefly bowing before turning around and following their father and the other man into the deeper parts of the Mansion.

The yard was quiet, jarringly so, especially with the words that were uttered from the seemingly ordinary man's lips. Kocho had an assistant aside from the girls at the mansion? She had a partner? What? That didn't make any sense! Wait... But hadn't they seen a man in the mansion who'd briefly appear in the background? Why was Sabito snickering about this too?

Hold it! This didn't many any sense!

And it seemed as if the others agreed as they all looked at her with puzzling looks

"Kocho-san..." Mitsuri's voice was low and quiet, tense, her anger barely restrained. She had never seen her like that before. 

"I don't like to curse but what the fuck was that?"

"Well..." She was taken off guard, obviously, this wasn't a reaction she was used to from her friend, maybe Shianzugawa but not her! "Well... That's my assistant obviously..." She looked around, sweating maybe they would just igno-

"It's obviously her partner! I can tell by the simple clothes he wears on his back!"As he said this, the silver-haired man snapped his fingers, jutting his thumb at his uniform. "You can? I don't believe it!" Kyoujuro stared up at the man in disbelief, arms crossed. 

"I can, I've seen similar yukata's at the shops I attend to buy my wives such gifts, and those are no scant price! Considering he's taller than my wives that makes the price exceeding!"

"Wow! That is an amazing deduction Uzui!" At the praise, the Sound Hashira visibly brightened, broadly grinning. "You shouldn't expect anything less than someone like me! I'd recognize clothing as flashy as that anywhere, I'm practically a connoisseur of clothing!"

Mitsuri however can only find it in herself to pout, hands displayed proudly on her hips as she glares at him. "Yet you still haven't hooked me up with your tailor!"

"There is no tailor baby, it's all my good fashion sense." To demonstrate this, he moved his hands to direct attention up and down his body with a charming grin.

"Don't call her 'baby'." Iguro hissed as Sabito guffawed in the background, nearly doubling over.

"Why? Jealous 'baby'? I can call you it too if it tickles your fancy," He slid to the side and wrapped an arm around the Serpent pillar's shoulder, quirking his brows at him as he leaned down. "What'dya say, baby? Me and you go to that taiyaki place nearby, and uh, let our mouths do all the talking?" This time, Sabito actually falls over, a grin exposing his teeth stretches across his lips meeting his eyes. 

"Get away you creep! Never in a million years!" He visibly shrinks away, wrenching himself away from as he speeds walks down the garden path, but with Uzui's wine-red eyes practically screaming mischief, he playfully gives chase. "So that just means I have to wait a million years! I don't mind that! What do you say we lessen it?" Iguro starts running and it's obvious that the Sound Hashira is taking joy in this since he doesn't put in the effort to catch up with him just yet.

Shinobu can't help but laugh at the display, the tips of her fingers covering her smiling mouth as sounds of joy escape it. Despite all of them with the exception of Tokito being adults, they act more like teenagers than actual adults, attention diverted so quickly but she wouldn't have it any other way. 

"Kocho," She jolted at her name suddenly being called and she whipped around to see who it was; it was Rengoku. "Yes, Rengoku-san?" She asked, blinking up at him. 

"Why didn't you te-"

"Oyakata-sama has finished his discussion,"

"Oyakata-sama has finished his discussion," 

The two girls walk out from the depths of the mansion, and Giyuu follows them, their master taking his time. No one says anything, everyone darts back with their parts and quits the unnecessary chatter. Giyuu walked across the platform, stepping down and sliding on his zori's, they were all too anxious waiting for their master to enter, waiting to kneel down in front of him and greet him once more. She guesses that's why she didn't see what was coming next. 

He walked in front of her, leaning down and laid a tender kiss on her cheek, leaning back with a small smile that made her chest roar with warmth and butterflies flutter in her stomach. He tilted his head a tiny bit to the side, the corners of his eyes crinkling, his eyes were hazy and tired, yet at the same time were full of adoration that made her heart skip a beat. 

"You also forgot your goodbye kiss," A little numbly, she unconsciously nodded at him watching him walk off, hands still clasped in front of him. 

Right before he turned the corner of the building, he bowed, while not as deep as when it came to their master. "Thank you all, my apologizes for the wait."

As he turns the corners that previous haze that filled her mind quickly deteriorates as she can feel the others staring at her, burning into the back of her head, before she could say anything the two girls interrupted her.

"Oyakata-sama has arrived,"

Instantly they all kneel, heads held down with bated breath as they wait for their chance to speak.

"My apologies for the interruption my children, we will now resume our meeting as planned unless any other miscellaneous activities are once more brought to my attention."

She opened her mouth to speak but Uzui beat her to the punch. "Fret not master, someone as flashy as you should pay no mind to the carelessness of others!" 

Their master only smiles, head tilting to the side as low chuckles escape his lips. "Of course, I'll keep that in mind. Speaking of flashy people, Sabito?"

She watched as the ginger, stilled, eyes wide he looked up at their master, nodding. "Yes, Oyakata-sama?"

"Are you available for staying after the meeting?" Shakily, he nodded again, this time more vigorously. "Of course Oyakata-sama!" 

Shinobu wondered what was on that letter Giyuu was holding as the meeting went one

A/N: Inspired by this fic/au of Civilian(but not really-) Giyuu and Demon Slayer Shinobu, there's another fic I'm working on that explains it more in detail but it's far longer than this one:

https://archiveofourown.org/works/28504311/chapters/69844668

if you enjoyed this then yell at me in the comments and tell me what you enjoyed about it. i would like to write more about this au if people are willing to see it but id like to know more of what you'd want to see.