Muichirou x Pillar!Reader from 

Thank you for requesting!

Happy Merry Christmas to you all!

Merry reading!

Don't check the comments. It's full of manga spoilers.

~~~~~

"I am the master of my fate,

I am the captain of my soul."

—Willian Ernest Henley, Invictus

~~~~~

"Eh, you're crying again, Mui-kun?" You rested your tiny hands on your small waist. Muichirou came running to you, engulfing you to a hug. 

He sobbed, "Nii-san's mad at me." You looked dumbfounded in his arms. You noticed a silhoutte approaching and saw that it was his father. You were picking some wild flowers nearby when Muichirou miraculously found you.

Muichirou's father greeted you with a wave, "(Y/N)-chan. I see Muichirou found you."

Hearing his father's voice, Muichirou turned to his father and told him about Yuichirou. His father tried to calm the crying Muichirou. 

You picked one of the flowers from the small basket you brought. You approached Muichirou and put the flower on top of his head. You had no idea where you're going to put it after all. 

"I'm sure Yui-kun has his reasons. So, stop crying." You approached him and hugged him. You patted his head, "I'll stay until you stop crying."

***

"Who are you?"

"W-what?"

You stared at Muichirou for the longest time. You've been promoted as the new Winter Pillar that stands as the foundation of the Demon Slayer Corps. All of the sweat, blood, and tears are the things that lead you to this high-ranking status in the Corps. 

When your eyes first landed on the colorful bunch of Pillars, you're attention were immediately snatched away by Muichirou, who was looking in the sky in a daze. You can't help but feel happy at the sight of a familiar face after the tragedy you went through your childhood. You didn't waste the chance of talking to him. Then, this happened.

 A nervous laugh escaped your lips as you patted his shoulder. "That's not funny, Mui-kun."

As much as you wanted to deny it, his serious and stern face said otherwise.

Your hand was swatted away from his shoulder. Your eyes widen, retracting your aching hand. Muichirou spat, "I don't know who you are, so don't touch me so carelessly."

He turned and walked away from you. You watched his fading frame with a shattered heart. There's no way Muichirou is forgetting you. Come on, he might be taking his joke a little longer. It's finally relieving to see a face from your childhood, then you're simply going to be treated poorly. How come you don't recognize me?

When he finally turned to a corner, you clenched your fist. When did you become so cold?

***

You were nearing the Tokitou's house. The sliding door opened, revealing a running Yuichirou. Yuichirou was so busy running from Muichirou he didn't see you on the way.

You fall on the ground with a thud. Your forehead was aching from the impact it received from Yuichirou.

"(N/N)-chan!" Muichirou ran towards you, ignoring his brother. He helped you up from the ground and started asking countless questions about your well-being. Rising from the ground, Yuichirou groaned. He massaged his forehead that also received the impact of your bodies smashing into each other. Yuichirou glared at Muichirou's back. 'He didn't even check me.'

Yuichirou appeared in your sight. He asked, "I'm sorry."

A giggle escaped from you, "I'm fine."

There was a beat of silence between the three of you. You suddenly remembered you brought something for them.

You exclaimed, "I want to give you two something!"

The twin's mother appeared by the door. "I didn't know you're coming over, (Y/N)-chan. Come in. You're right in time."

"Right in time?"

Muichirou suddenly took your hand and pulled you inside. "We're going to eat lunch!"

When all of you finally settled down, you took this chance to give your gift to the Tokitou brothers.

"What's this?" asked Yuichirou, holding a beaded-bracelet with a pendant.

"sO pretty!" said Muichirou, raising the pendant high. The light peeking from the window reflected on the pendant. Muichirou noticed something in it. "Is this a flower?"

You pulled out yours. You explained, "A Periwinkle to be exact. Mother created them for us! She said we can have this as a friendship bracelet."

"Okay."

"I'll treasure it forever, (N/N)-chan!"

The three of you wore the bracelet. "This is the evidence that we're best friends forever!"

***

You fiddled the bracelet in your wrist.

"I'll always be by your side."

You pursed your lips at the memory you three swore when you had to move away. Muichirou and Yuichirou were too sad to even talk to you.

"Earth to (Y/N)-chan!"

You flinched from your spot on the chair. "Y-yes, Mitsuri-san?"

Mitsuri grabbed both of your hands. "There's no need for the honorifics! We're both Pillars after all." She pointed towards a ramen shop. "Let's eat!"

"Okay."

Mitsuri and you placed your orders. You were surprised at how many bowls of Ramen Mitsuri ordered. The two of you patiently waited for the ramen.

Seeing this opportunity to know you, Mitsuri asked, "How are you related to Muichirou-kun?"

First question, it's about Mui-kun already! You averted your eyes from Mitsuri. You answered, "We're childhood friends..." a bitter smile appeared on your lips, "...He doesn't remember though."

Mitsuri panicked at how the topic dropped your mood. She mentally searched for a way to cheer you up. "Muichirou-kun is always like that. He's always alone. I guess it will be refreshing if you try to talk to him sometimes."

A realization hit you. "Then, he might remember me."

"Yeah!"

One of Mitsuri's ramen bowls and yours were placed in front of you. Mitsuri beamed at you, "Don't give up, no matter what happens!"

A sincere smile appeared on your face, much to Mitsuri's happiness. "Thanks, Mitsuri."

***

"Good morning, Mu—Tokitou-san!" you greeted. You beamed at him. The two of you coincidentally met at the gate of the headquarters and you took it upon yourself to go in with Muichirou. Though, it was hard not to call him by the nickname you gave him.

"Good morning..." You smile faltered when you sensed he didn't remember your name. Once again, you introduced yourself, "I'm (Y/N) (L/N), the Winter Pillar."

He nodded and walked past you. You puffed your cheeks as a pout settled on your mouth.

You went in front of him, blocking his way towards the house. He frowned. "Do you need something?"

You pointed yourself as you spoke, "Just call me, (Y/N) from now on." You paused, hesitating your next words. "And... Can I call you Mui-kun?"

Muichirou tilted his head to the side, "Isn't that what you called me before?"

"You remembered?"

He didn't answer and walked past you again. You crossed your arms and followed him quietly.

When the semi-annual meeting of the Pillars finally ended, you approached Muichirou again. 

"Mui-kun. Do you want to eat together today?"

"No."

You stopped walking. You clenched your fists. Calm down. Calm down, (Y/N). You can do this. You took a deep breath and smiled again, skipping past Muichirou to approach Mitsuri and Shinobu.

She didn't pester me. thought Muichirou, watching you converse with Mitsuri and Shinobu. Somehow, Muichirou felt uneasy. You sure gave up easily in becoming his friend. 

Deep down, Muichirou was disappointed.

***

"So, this is where his estate is located," you mumbled, observing the surroundings. You arrived in front of Muichirou's estate. 

You gulped and held the bag of cookies tighter. I hope he likes this.

You called out, "Mui-kun?" No one answered. You tried again and it was the same result.

Finally, you decided to welcome yourself. 

"What are you doing here, (L/N)-san?"

A squeal escaped your mouth. You almost dropped your beloved bag of cookies. You turned around, seeing Muichirou standing with an origami paper in his hands.

"Didn't I tell to just call me (Y/N)? Anyways, I came here to drop off something."

You gave Muichirou his bag of cookies. There was silence between the two of you. You finally noticed the origami paper in his hands. A smile crept on your lips, "You're making origami! Can I make too?"

Muichirou reluctantly agreed. He led you towards the living room, where there was a stack more of origami papers. He saw how your face brightened up at the sight of the papers. He silently put down your bag of cookies as he sat across you. He eagerly watched your every hand movements, slightly thrilled to see what you were making.

"Done."

Muichirou's eyes widen. Not because of the paper crane you made, but because dangling pendant on your wrist. It was the same as he was wearing as of the moment. He never had the heart of removing it. It's like he'll lose something very important in the moment he takes it off. 

Muichirou pointed at the pendant, "That bracelet..." 

You lowered the paper crane. "Oh this? It's a friendship bracelet."

"I see."

"Why? Is something wrong with it? Don't tell me it's broken!" You started checking every part of the pendant for slight damages. 

Unfazed by your antics, Muichirou said, "I have the same bracelet."

You stopped from looking. You looked at his cloudy teal eyes. He still has it? You politely asked, "Um, can I see it?"

Muichirou raised his right wrist. There, reflecting the sunlight peeking in the room is the very same pendant you gave to Muichirou and Yuichirou that day. A relieved and gentle smile graced you features at the sight. He still hasn't forget everything.

An unknown feeling flooded Muichirou's chest at the sight of you smiling at him. He can't explain it, but he can tell it was good. He suddenly felt the urge to hug you right there. 

"I want to tell you something for a while now, Mui-kun."

Muichirou tilted his head, "What is it?"

You let out a sigh before you looked to him with a determined expression on your face. Muichirou was confused why you were having such an expression. 

You told Muichirou about everything you know. You told him you were his childhood friend. You told him he has a twin brother. You told him of the many things he isn't even aware of.

Then, you stopped.

"What's wrong, (Y/N)?"

You shook your head. "I just realized it's too much information on your part. I got carried away. I'm sorry. But..."

You held his hands and smiled at him, "We promised we will never leave each other's side and I'm planning to do that."

At that time, Muichirou was rest assured that he'll find himself very soon.