A/N: Hey! This is my first Demon Slayer fanfiction. I hope it's not too cheesy and I apologize in advance for any grammar mistakes. The story will focus on Giyuu x Shinobu, but I also paired Sanemi x Kanae and Obanai x Mitsuri. There will be others added. So please, no hate if you don't like these ships. Enjoy readers!

Disclaimer: I do not own Kimetsu no Yaiba/Demon Slayer or any of the characters.

Warning: This story contains spoilers from the manga, sexual content, and strong language.


"Eh? Dating? Since when, nee-chan?!" Shinobu exclaimed in a state of awestruck.

Kanae sat on the deck, swinging her legs over the edge, and hummed to herself. After a long pause, the twenty-one-year-old looked up and saw the first star of the night appear in the sky.

"A few days ago, I suppose." She responded, then tapped her index finger against her lips in a thoughtful gesture. "If I recall correctly, I've already passed the legal age to marry. Naturally, it is my duty as a woman to wed and produce an heir. Besides, my duties don't only lie with the Demon Slayer Corps. So, better make use of myself while I'm still alive."

Shinobu was silent for a long moment. Frankly, she wasn't huge on the topic of marriage, due to her strong desire for revenge. The intense hatred she harbors for demons prevails over emotional intimacy. For that reason, the insect hashira was unable to live a normal life as per her sister's request. Instead, she decided to devote all her energy to finding the demons and defeating them for good. Three years ago, a upper moon demon by the name of Douma mortally wounded her sister in battle. If Shinobu hadn't arrived in time to mend Kanae's wounds, she would've met her maker that morning. To Shinobu, losing their parents was bad enough, so she couldn't cope with her sister dying on her as well.

While sitting there in a daze, she thought about how life could've been if she wasn't there in time to save her life. These special bonding moments between her and her sister were something to look forward to.

Kanae cocked an eyebrow at her younger sister who had a deadpan expression on her face. She thought Shinobu would be happy for her, but her expression showed otherwise.

"I thought you of all people would understand what's at stake here." Kanae muttered with the slightest hint of disappointment in her tone.

"Pardon? Who in their right mind is thinking about marriage and children at a time like this, especially when Muzak is still out there?" The eighteen-year-old questioned, out of curiosity.

The flower hashira sighed deeply. "Just because there is a power-hungry demon on a war path doesn't mean that our legacy has to end with us. Someone has to protect the family's bloodline from cease to exist." She explained before glancing over at their youngest sister with a carefree smile. "Don't you agree, Kanao?"

"..."

Kanao was still gazing at the night sky with her eyes in awe. Her hair, pony-tailed to the side was quite cute, Kanae thought. Unfortunately, it wasn't until shortly thereafter when the sixteen-year-old realized that Kanae was asking for her opinion on the matter.

She fixed her gaze on her adoptive sisters and tilted her head to the side with a puzzled look and smiled back.

By then, it was obvious to the Kocho sisters that Kanao's mind was someplace else.

"Ah. I don't think she heard us." Shinobu spoke quietly enough that Kanae was the only one to hear her words.

Kanae exhaled slowly, "Not in the slightest."

Shinobu took this as a neutral answer from the flower tsuguko(successor) and ran with it anyway. Her eyes closed as she let out a contented sigh and smirked to herself. "So! Don't you think I have the right to know who had the balls to ask my big sis out?"

Kanae scratched her cheek, which was turning bright red after she mentioned this question.

"Sanemi Shinazugawaz," she released from her lips.

"SANEMI-SAN!" Shinobu uttered out suddenly.

The insect hashira was shocked. Her wide eyes almost consumed most of her face as she stared over at the flower hashira in disbelief. "I don't believe it!"

Kanae bashfully covered her face with both her hands and gently swayed her body from side to side. "So embarrassing! Don't look at me like that, Shinobu!"

Shinobu's face flushed in the process. "Embarrassing? Something this big, how did you hide it from me?!"

These words caused Kanae to twiddle her index fingers together, "Well..."

"I think that's great, nee-chan!" Kanao exclaimed, beaming with pleasure. "It's about time Sanemi-san asked you out with intentions of marrying you. I feel a weight has been lifted off your shoulder now."

"Aww, thank you little sis." Kanae bashfully spoke, grinning from ear to ear.

Shinobu quickly averted her eyes to her younger sister. "Nani (what)! You knew about this too?"

Kanao nodded, "Hai (Yes)! Sanemi-san always invites ane (older sister) out for ohagi after every mission together. Ane gladly accepts his invitation and Sanemi-san blushes as he always does. He even asked me if I knew what her favorite flower is."

"I see... Where was I through all of this?" Shinobu asked, rapidly looking back and forth between them both.

"On a mission like always," Kanae reminded the insect hashira. "You barely around to know what goes on at the butterfly estate anymore.

Her mouth parted slightly in disbelief at her words. "And that's my fault, how? I can't exactly turn down a mission when I am assigned one."

"I know, Shinobu... but sometimes you voluntarily take on a mission without hesitation," Kanae voiced her concerns. "When do you have time for the family anymore?"

Shinobu was about to make a valid point about that night by pointing out her index finger as she opened her mouth to validate this question, but Kanae beat her to the punch.

"Not counting tonight, my darling sis..."

These words caused Shinobu to gape at her excessively. Eventually, she stood up in a hurry and turned her nose up in the opposite direction in defeat, while clearing her thought. "A-hem!"

Kanae noticed Kanao casting an almost worry glance in her direction. The flower tsuguko couldn't remember the last time Shinobu appeared so flustered. Most of the time she always seemed so composed about everything. Not to mention, her poise expressed utmost dignity and grace. Kanao wished she could be more like this instead of flipping a coin to decide her fate. She always admired the insect hashira for how strongly she carries herself.

Shinobu took a deep breath and let it out slowly, as she pondered on how to express herself, without it coming out incorrectly. "Because, I have to... I must release these demons from their sufferings," she declared under head breath. "I may be small and unable to cut their heads off myself, but the poison I've created is enough to put them out of the misery... I won't rest until I fulfill my purpose as a hashira... even if it does kill me."

Kanae frowned with a hand resting on her cheek. "Oh my... I had no idea you still felt this way. I thought since you allowed Tanjiro-san and his sister Nezuko-chan to stay at the butterfly mansion that you were learning to accept that not all demons are awful and need to be killed. My expectations were too high."

Shinobu glanced over her shoulder at her. "That's different, nee-chan. Nezuko-chan showed a lot of restraint at the meeting that day. She's not exactly liked the others, but I still must keep a close eye on her. That's the whole reason I allowed them stay at the butterfly mansion... Plus, if I had to be completely honest with you, Tanjiro-san does remind me of you a lot."

"Still... It was very selfless of you to let them stay," Kanae clarified before tapping a forefinger against her chin. "I haven't got the faintest idea what let on this change, but I like it. You even took the night off to spend time with your sisters... So, I'm wondering if someone influenced this turn of events."

Shinobu smirked playfully and chuckled to herself softly. "I'm afraid I don't kiss and tell."

Shortly after, Shinobu morphed from her human form to that of a beautiful butterfly with white, turquoise, and light purple wings quite like her hair accessory. She sets off into the night, leaving her clothes discarded on the ground behind her.

Kanae and Kanao watched as she floated upwards and disappeared into the night sky. She always had the tendency to discard her clothes without warning and leave them on the ground, they thought.

"Ehhhh! Shinobu, get back here! What am I supposed to do with these clothes?" Kanae yelled aloud.

(Later that night)

The sky darkens that night. The moon was full and gave off more light than any other night before. To Giyuu, it was surprisingly still, and the air was slightly chilly to say the least. He was walking the streets of a small town by the butterfly estate when he noticed a young male walking funny, as if a leg had been broken. His heavy breathing caused the water hashira to stop in his track. Something was off, so he carefully placed a firm hand on his sword and waited for the right moment to intervene.

The young male stopped walking and looked up at the moon for a second. His stare slowly turned into a look of horrified realization. He glanced downward fearfully as his hand slowly morphed into black, intimidating claws before his eyes. Not long after that, he shrieked in a high pitch voice while throwing his head back in pain.

Once, Giyuu realized what was going on, he took one step forward and accidentally stepped on top of a twig in the process.

The demon swiveled around and saw Giyuu standing there with a threatening hand on the handle of his blade. The pupils of the demon's eyes were completely dilated with pulsating veins around the temple. He also had menacing sharp fangs that weren't appealing to the water hashira eye's, especially since it was foaming at the mouth.

Instinctively, the demon felt killing instant from the water hashira who looked fixedly before him. The look of pure terror crossed the demon's eyes and Giyuu noticed this right off the back. It was clear that this young individual didn't want to become a demon from the start. There was only one way to end a demon's suffering after they willingly surrender. Giyuu didn't take pleasure in slaughtering the weak.

"Water breathing... Fifth Form... Blessed Rain After the Drought!"

Giyuu crouched down, while changing the grip on his sword as he lunged towards the demon with a terrifying speed. Within seconds, he decapitated its head off in a single flowing strike that caused little to no pain for the newborn.

He drew his arms apart with the sword still in his grasp as his feet came to a standstill behind the demon.

Giyuu carefully looked over his shoulder at the dismembered body falling onto a bed of crimson leaves. The demon that was once a human adolescent gazed up at the moon with tears of relief in his eyes, as he slowly vanished into thin air.

"Thank you..." he murmured these last words.

"Pity... he wasn't much older than Tanjiro," said Giyuu as he wiped the blood off his sword and put it back in its scabbard.

"GOMENASAI (I'M SORRY)!"

The water hashira peered over at the shadowy figure running straight towards him through the trees and brushes. It wasn't long before he realized who it was with a horrific look on his face.

It was Tanjiro.

"Giyuu-san! Thank goodness! Help me!"

Tanjiro immediately hid behind Giyuu, clinging onto the back of his haori for dear life.

Giyuu already confused face furrowed with drawn eyebrows. "Nani?"

The leaves from the brushes started to rustle before they heard unidentified man yelling from a far. "I'M GOING TO KILL YOU, TANJIRO! WHERE ARE YOU HIDING, YOU LITTLE SHIT!"

A swordsmith by the name of Hotaru leaped from behind the brushes with two extremely sharp knives in his possession, which indicated that he intended on stabbing Tanjiro that night.

"Oh no! Please, save me!" Tanjiro pleaded with tears in his eyes, clinging on to him like tomorrow wasn't promised.

"There you are Tanjiro-san... I have a bone to pick with you!" Hotaru grumbled as he stalked towards him with no remorse. Tanjiro could almost sense a murderous smirk behind that hyottoko mask of his.

"I know and I'm sorry!" He repeated in an apologetic tone and pressed his hands together. It never once crossed his mind that Hotaru would be this easily enraged by a broken sword.

Out of awkwardness of his own, Giyuu flashed a palm in front of Hotaru to get him to stop in his track. "Halt! Why are you trying to inflict harm on my tsuguko with kitchen knives?"

"Fuck you, pretty boy! It's probably your fault that he can't wield a sword! Therefore, I hate you!" Hotaru retorted in a heated gesture.

Giyuu looked at him with a deadpan expression. "I see... You're not very nice."

"Screw you! I will skin you alive here and right now," he raged on.

Tanjiro tugged on the back of Giyuu's haori and whispered in his ear. "Giyuu-san, what should we do? He's upset that I broke the sword he created for me."

The water hashira placed his thumb on his cheek and cupped his chin with his index finger, stroking his unimpressive stubble thoughtfully. Not long after that his fist smashed into the palm of his hand.

"I got it!" he proclaimed.

Tanjiro places his hand over his chest and let out a breath that he was holding in. "I'm glad."

"We're going to run for it," Giyuu revealed with an aloof expression and nodded thoughtfully.

Tanjiro's face went blank at first. But then he thought about his plan a little better and concluded that it wasn't such a bad idea. The fact that they weren't far from the butterfly estate made him feel more relieved. A good distraction would give them a chance to escape, so he thought of one.

"Look! Is that a mitsarashi dango food stall on the corner there?!" Tanjiro exclaimed with his forefinger jabbed in the direction behind Hotaru's backside.

Hotaru immediately twirled around and beamed with joy in that direction. To his dismay, there but a couple of sharp leaves soaring through the air.

This infuriated him to no end. As it turned out, they had already left before he got another chance to go after them.

"Forgive Us! We're Sorry!" Tanjiro screeched as they scurried towards the butterfly estate.

Aoi opened the side gate to let Giyuu and Tanjiro inside. It didn't take long for them to quickly grasp her small hand signal as they ran straight through it. She swiftly closed the gate just before Hotaru got the chance to catch them go through it.

To be continued...