Hello!

It's my first story for the Kimetsu no Yaiba fandom!

It's a Giyuu X Shinobu fanfic, I hope you like it!

The first time they met, they just stared at each other.

"This is Kochou Shinobu, she is the little sister of the flower pillar Kochou Kanae. And this guy here is the new water pillar, Tomioka Giyuu."

They continued staring, even after they had been introduced.

Oyakata-sama just laughed.

…

One month after Giyuu entered the pillars, Kochou Kanae died to the hands of the upper moon two. He didn't grieve, of course it was a big lose to the pillars, but he didn't got to know well enough the flower pillar, so he couldn't say he was really sad.

But, he saw Kochou Shinobu crying a lot while hugging her sister's haori, and well...he just couldn't leave her alone now, because what he saw was a reflect of his past. He sat down on the wood floor of the Butterfly Mansion, he would just be there for her.

"What do you want?!"

"Nothing."

"So leave!"

She wasn't really angry, and he knew it, she was just sad.

"I know, it's difficult…"

"You don't know anything!"

"Yes, I do."

Shinobu stared the water pillar, and she finally understand why he wore a mismatched haori.

"...Thanks…"

Weeks later, Kochou Shinobu was wearing her late sister's haori.

…

"Tomioka-san!"

He didn't understand why the eighteen years old girl liked to follow him around even when they weren't in a mission. For some reason after the night where he just stood there in the Butterfly Mansion 2 years ago, Kochou Shinobu just started...annoying him.

What he did? He didn't know either.

"To-mi-o-ka-san!"

He tried to ignore, but she was insistent.

"Are you hearing me, Tomioka Giyuu-san?"

Well…

"Yes, I'm hearing Kochou." He said, finally turning around to look at the short girl who laughed at his annoyed expression. She got what she wanted.

…

Kochou Shinobu was really different. Before her sister death, she was like a tomboy, always angry and harsh, he even though that she was a boy when they first met.

But now, Kochou Shinobu was really feminine, delicate and dangerous, she was the only pillar who couldn't cut a demon's head, but the poison in the katana make up for this problem, and she would became more dangerous when pissed off. And for some reason that he could not understand, usually he was the one to evoke her fury...but...

...even when she was angry, she had a smile in her face, it was like she was pretending to be like her late sister, and it really irked him.

"What are you looking, Tomioka-san?"

"..."

"...what are you looking, To-mi-o-ka-san…?"

"...you changed…"

"And?"

"...you are really feminine now…"

"...Oh...thank y…"

"...because two years ago I really thought that you were a boy and..."

"..."

"..."

"Tomioka-san?"

"...yes…?"

"Have you ever got poisoned?"

"..."

She was really dangerous under the mask of a smile.

…

They got the mission in the mountains, they were supposed to help the other ranks of demon slayers that were disappearing, he would never ever guessed that he would cross paths again with the boy whose sister became a demon.

"What are you planning, Tomioka-san? You know that right now you're going against the rules, right?"

"..."

"We are demon slayers, and even so, you just let a demon escape. You could at least explain yourself, Tomioka-san."

"...I believe it was two years ago…"

"This is going to be a problem if you are going to start from such a long time ago. This is harassment. You just have a grudge because I said that everyone hates you, right?"

He was shocked again, this girl...she really have a sharp tongue, no? But...well...at least she wasn't trying to disguise her anger or frustration under the mask of a smile, not in front of him at least.

They were improving…

A blade came off the sandal that she was wearing, if it wasn't for the crow's message, she really would have stabbed him.

...they were improving...a little bit.

…

Usually pillars doesn't go in missions together, but for some reason Oyakata-sama was sending they in pair in the last missions.

Why? He doesn't know, but since it was a order he couldn't say no, and well...he, Tomioka Giyuu never thought that he would say it, but sometimes company was a good thing, even if the company goes with the name Kochou Shinobu.

"The mission wasn't so difficult. I wonder why Oyakata-sama send both of us." Said Shinobu sitting on the wood floor.

He didn't know either, but sometimes it's good to have someone who have your back...then again, Kochou Shinobu would stab him if she got annoyed, so...would it be really good to work with her?

…

"We were training." said Giyuu.

"And then this dog appeared, and for some reason it attacked Giyuu-san!" continued Tanjirou "And I don't even know why! Giyuu-san did nothing!"

"Ara ara Tomioka-san, it's seems that even animals disliked you." said the insect pillar smiling, even so, she got some medicine and bandages to put in the injuries.

"Dogs doesn't like you either."

Tanjirou and Shinobu stared at the man, never, NEVER they heard him retort like that.

"Oh…"

The Kamado could feel a strange vibe coming from the woman by his side, he doesn't need to smell the air to understand that Shinobu was pissed by Tomioka's answer. That's why he left the treatment room and just sent a mental "good luck" for his senpai.

The next day, Tomioka Giyuu appeared with a lot of bandages.

…

They were training day after day, because Muzan could attack at any moment, and well...it did happened.

After hearing the explosion in Oyakata-sama mansion, they sent their crows to deliver a message.

"I don't dislike you." said Shinobu's crow.

"Don't die." that was Giyuu's crow reply.

"Of course he wouldn't give me a reply." Shinobu laughed, and a tear rolled down her check. "I'm sorry."

...

"Dead! Kochou Shinobu is dead!"

No…

No.

No!

He just couldn't believe that, the crow must be wrong, because Kochou Shinobu was...no, IS strong!

"She died after a confrontation with Upper Moon Two!"

He heard Tanjirou gasp for air again, and finally the weight of those words sank at his heart.

The annoying girl who was always making fun of him, but was kind enough to make sure his was always healthy, The Insect Pillar, Kochou Shinobu...was dead.

…

The dawn finally arrived, and the battle was over. They did it, they fought Muzan till the sun rise.

The first demon of history was dead.

But…to defeat Muzan, a lot of people died, some were probably scarred for life, and everyone lost something, including him. The pillars were crying, his juniors were crying, hugging each other because right now they needed some comfort, and he, Tomioka Giyuu finally gave himself permission to cry.

He was awkward about human interaction, he was a man of few words, and usually he was misunderstood because of it. He spoke only when necessary or when he had something important to say, but there was something that he never told her, and now he deeply regrets.

Because in that battle he lost Kochou Shinobu, the one who he loved the most. If he had know that this would happen, have he told her how he felt? Would things be different? He didn't know, but in another life he hoped that he could tell her about his feelings.

…

He blinked.

And blinked again, because he was crying in his sleep...again.

He really should stop watching samurai's movies because lately he was dreaming that he was one, fighting monstrous creatures using a blue katana and a strange half and half haori. But...he was always fighting with someone in his mind, a girl, whose face he could not remember.

He got up of his bed, and went to the kitchen to make some coffee, he needed to wake up properly, Forget the dreams, he told to himself, he doesn't need distractions today, because today was his first day as a teacher in Kimetsu Gakuen.

…

For some reason, the teachers looked a lot familiar, but Giyuu couldn't say why, and the director, Oyakata-sama too. But okay, it was probably his imagination, in Japan now people wore a clothes that resemble more a cosplay or have different hair color, like blue or pink.

But in school no.

"Do something about your hair!"Giyuu said to a blond boy.

"It's natural!"

"You can't use earrings at school!"

"But it's a present from my father!"

"You can't use a boar's mask at school!"

"I don't care!"

"You can't come eating a bread!"

"Hum hum."

What the hell was wrong with those students? All were...very peculiar...would someone be normal...at least as much as possible?

"You will get tired before the classes. Everyone here is a little bit different."

Blue eyes found purple ones, and for an instant Giyuu couldn't say anything, because he remembered...everything.

"...Are you the new teacher?"asked the girl.

"...yes."

They just stared at each other, and this scene was really familiar.

"...You're strange."

"You shouldn't say this at yours teacher face."

"So if I say it when you are not near it's okay?"

"..."

"..."

"You're annoying."

"And you shouldn't say this at your student face."

"..."

"...but...we're even now."

Giyuu sighed and the girl just laughed.

"Kochou-senpai! Kanao is looking for you!" yelled a girl.

They stared at each other one more time before Giyuu spoke.

"You should go, Kochou."

"Okayyyy...see you...To-mi-o-ka-sensei."

He looked at her back, she was the same as ever, and he was really gladly.

...

Minutes later Giyuu was about to lock the gate when suddenly he remembered that he never told Shinobu his name.

He couldn't hold back a smile.

In this life, they would be fine.

Hope you liked it!

And sorry for possible grammar errors!

English is not my mother tongue