Day 2: Broken Promise

For Zenitsu, he cherished the looping tunes in his head more than anything else.

It was only natural. Being born with a defective voice box made it difficult for others to really hear him otherwise. He talked, he talked a lot actually, but speaking was a foreign concept to him. What came out were only half dead grunts accompanied by tiny intakes of air. Sometimes he wondered what kind of person he would've turned out to be if he had a voice. Most of the time, he was more curious if the people around him were talking without actually speaking, kind of like him.

To think that it all started with that singular thought. He'd always had sensitive ears but connecting those sounds to emotion soon became second nature. As Zenitsu listened more and harder to compensate for the silence of his own, he found thoughts and feelings born from his perception of others. Old lady Sakura-san sold Gramps and his three adopted grandchildren pies and had the sweetest smiles. Slowly, that image had shifted as Zenitsu could hear her boiling veins whenever Kaigaku was around, almost like she wanted to give him a kick in the shin. The neighborhood mailman's quickened heartbeats made the fact that he was having an affair with the woman across the street all the more damning to Zenitsu. That cat on the rooftop was thinking about her next meal.

Everything around them spoke these words that seemed so obvious to Zenitsu. It was obvious in their sound. He could hear malicious thought hidden behind nice words, or unrelenting sadness shoved out of sight. It wasn't until Kaigaku bragged to him one time about how much Sakura-san loved him and the woman's husband came back every morning none-the-wiser that Zenitsu realized he was the only one.

He had tried to warn Kaigaku not to irritate Sakura-san any further through hand signs and writing. He tugged at their neighbor's sleeve while insisting what he heard. However, no one believed him. They never listened. It was hard for anyone to believe Zenitsu.

That was why he was so relieved that his soulmate was the one person who he could truly talk to without actual words being spoken. For you see, any song that is at the forefront of your head would become stuck in your soulmate's mind and vice versa. It was perfect. Sometimes Zenitsu spent hours just sitting in his room and sending out every tune he associated with those around him to his unsuspecting soulmate, hoping and praying that the other would understand.

Occasionally, it seemed that the one on the other end of the line did. Zenitsu loved to wait as melodies rang back at him, some exuding sympathy while most held a kindness that he couldn't interpret as anything but comforting. No matter how frustrated or scared he got, he always felt his shoulders relax to such tunes.

On the night after Gramps had passed away, Zenitsu was left playing the sadness of his heart out. He didn't have a name for the song. Just that it was the mess of his brain that charged every part of his being and output itself into the notes on his violin. It was raining. Zenitsu had never felt his world go so quiet before. And through the silence of his heart, he heard one single chord play back at him.

Please don't give up. I know it hurts but I promise it'll get better. I promise I'll be there for you.

It was a beautiful song. So kind and gentle that Zenitsu wanted to cry. To others, it would be dumb to hear words coming from the song. But for Zenitsu, the message rang so loud and clear in the pit of his soul that he couldn't help but take them to heart.

So he didn't give up. He didn't rush home immediately after school anymore, opting to hang out with his classmates like Murata, Kanao, and Genya who didn't mind having a mute tagalong. He even joined student council. Without a voice, the most he could do was help organize events. He was still abhorrently gross to the female population for the sappy love letters he wrote to all of them, but he didn't stop. And for a while, things really did get better. Somehow, the times that he'd sit alone in his room sharing music with his soulmate felt all the more compelling.

When Kaigaku would interrupt what he called his 'freakish alone sessions,' it wasn't a big deal. He'd scoff at Zenitsu and say he was wasting his time again. When Itoka, his adopted sister did, it was a completely different ballgame. She always insisted on staying and asking about every little song that Zenitsu both sent and heard from his significant other. It helped that she was also adorable. Zenitsu was so proud to call her his little sister. The blond could do not much more than bring out his old violin and play the tune to the best of his ability.

Whenever he finished, his sister would have stars in her eyes. Itoka was always bright. It felt like she was reaching for heights that Zenitsu could never even fathom. "That was amazing, nii-san!"

He signed, saying it wasn't a big deal.

Each and every time, Itoka shook her head. "It definitely is! Hey, I've always wanted to be a singer. I know Kaigaku has been taking guitar lessons lately. He has a lot of music classmates who would love to join in. How about we start a band?"

Zenitsu flinched back. Oh no. Definitely not! He'd die before he even made it to the stage! What if he embarrassed himself?! They'd become a laughing stock and then Kaigaku would hate him even more. Plus it's not like he was actually that good at music. He just did it a lot, used his ears a lot, because he had nothing else to express his feelings. Doing that kind of thing but in public was scary. Putting yourself out there for millions of people to judge was out of the question. He couldn't do it. He can't.

Itoka stared bewildered and trying to discern the words coming from Zenitsu's spastic hands. After a while, she sighed, bringing them down to look at her brother with pitiful eyes. "How about this? Kaigaku and I can do all the public rep stuff. You can write and compose our songs for us! That's just as important."

The blond reeled back. Actually, that didn't sound like a bad idea.

The younger girl smiled. "But, I think that if you told too many people that you were the composer, they'd want to talk to you too."

Zenitsu froze. No. No, he definitely didn't want that.

She sighed. Her tune took on something that he didn't recognize. "Then we'll keep it secret. Just between the three of us. Come on! I really want to do this but we need you! I'm sure that you'll do really well, nii-san!"

Itoka really was such a good girl. He was glad she was here to support him.

Hesitantly, he nodded, smiling adorning his face.

That was how the star sibling trio began their rise in fame with a few boys from Kaigaku's band class joining in with cheers. Kaigaku wasn't as graceful with his notes as Zenitsu was, complaining about the complexity of the chords with an ugly colour of jealousy until Zenitsu was forced to hesitantly change them. On the contrary, Itoka nailed every note with her singing voice like she was an angel from heaven. It was a weird dynamic to get used to. However, for Zenitsu who could come up with songs on the fly just from listening to the breathing patterns around him, it wasn't impossible.

Itoka was the one who truly brought their band to the light in his opinion. With her button nose and short peach-coloured hair, she became the face of their group. With that fame came the inevitable rising standards in how the three presented themselves. Kaigaku didn't change much, opting to go with the (and these words were totally on purpose from Zenitsu's part) asshole role that wasn't too far off from his initial personality. Some part of him liked to think he was doing it to prove himself the best but most of him just enjoyed the ego trip. That's what Zenitsu could interpret from his sound. Still, his actions with staying in the team made the blond smile.

It was a massive culture shock. All three of them were orphans. Surviving on bread crumbs, fighting amongst each other on who could have a pair of shoes, and living on peanuts made for a rocky transition to suddenly having what felt like all the money in the world from each successful gig. Some of them took it better than others. Zenitsu splurged on his favourite sugary snacks and tried to lavish girls that he liked with even more pricey gifts. (hey, it had to work someday, right?!) Kaigaku overhauled his room with the most expensive of game systems and purchased an impressive car to show off to his friends. He became more unbearable in some ways, throwing money in hopes to catch up to Zenitsu's skill with the violin.

"Ha, I knew this crappy song you wrote was a piece of cake! I just needed some time to get used to it." Kaigaku would brag at least once a week. Not that Zenitsu had a say in the matter, but he kept his mouth shut about how Kaigaku left every Thursday night for advanced and costly guitar lessons solely for the purpose of learning a chord that he couldn't play before. It was admirable. He was a pain. He sometimes hated him. But he was still his brother.

Itoka was a different story. At fourteen, she was the sweet girl next door who wore her hair in dollar store scrunchies and paired her jeans with jackets adorning little cartoon bunnies printed along the sleeve. At eighteen, a different shade of dyed strawberry blond hair would assault the brothers' eyes every other week. Skirts that cost more than what Gramps used to be able to afford in groceries for the month and sweetheart necklines that showed her chest more and more had the two squirming in discomfort. This was their little sister, for Pete's sake!

Zenitsu signed as such one quiet evening after Kaigaku had retired for the night and left the two of them cleaning the plates of their childhood home. Well, it was more like Zenitsu was the one cleaning the plates. Itoka sat aside with her face near her phone, scrolling on her feed and typing comments. She doesn't notice the flailing of his fingers. For the first time in Zenitsu's life since living with her, he felt like she wasn't listening.

Evidence of such came in the form of a shriek in excitement. After covering his ears, she shoved her phone at him with wide smile and flush adorning her cheeks. "I can't believe it! It's Kimetsu no Yaiba! We got a deal to play a song for Kimetsu no Yaiba!"

Zenitsu frowned. He didn't appreciate being ignored! It was a slight against not only himself but every socially awkward person in existence. He tried to express that in his face. However, it probably came out more as a grimace. He would sign again but Itoka already shoved several notebooks in his hands, kitchen cloth falling forgotten to the floor.

"We have to hurry! They need this done by the end of the month. Just a sample of us playing the opening song is enough for the meeting with everyone next week." She squealed again, spinning on the spot. "I can't believe it. We're meeting the director! The actors, oh my god… can you imagine meeting Giyuu or Tanjirou? I would die-" Pausing in realization, she screamed in terror. Was Itoka always this loud? "Oh my god, that's next week!" Repeating those two words like they were a mantra, she rushed out of the room with nothing but whispered notions about booking an appointment with the stylist.

It really was a big deal. Although playing in cafes and shows was its own thrill, being able to work with a studio and have their song broadcasted in the backdrop of such a substantial character moment for the world to hear would etch their music in the memories of many. So, on the day of the initial screening, Zenitsu put some effort into his looks as well. Although he didn't often think there was a point, Kaigaku and Itoka took all the attention anyway and there wasn't much clout in trying to pick up girls with an opening line as amazing as being the backstage manager, Gramps would positively kill him if he ruined everyone's chances! He had to be there even if in the background to at least take notes. He washed his hair, tried to style it at least half-decently, and wore a dress shirt that Kaigaku had haphazardly thrown at him after finding a better one.

The three of them showed up to the shooting in their best casual clothes. The idea was simple even though they'd never done something like it before. Zenitsu would ask a few questions about the intent of the song and context of the scene. It was the interview that would be scary as hell. Even now, Zenitsu shook in his shoes in fear. He didn't ask for this, damn it! But Kaigaku and Itoka were here! He had his whiteboard and notebooks ready, everything would turn out fine.

It didn't turn out fine. Not when Kaigaku left to check out the set while Itoka didn't waste a moment to mingle with the cast. That left Zenitsu alone. He can't believe it! Less than a minute and he's already been abandoned! They both know that he can't handle himself in normal conversations with random people. It was terrifying, he felt like running away screaming bloody murder every time it happened. Yet, they still left him behind. He was positively going to rip into his siblings with the most passive-aggressive glare that they'd ever felt in their lives! Not, not that they'd listen. He paced in circles, fuming at the two.

"Would you happen to be the band: Thunder Pillars?" The blond flinched. Straightening up, he came face to face with three people, two of which were eyeing him warily. Zenitsu scrambled for his paper, about to write a message when his ears are suddenly assaulted by wind chimes blowing in the wind.

It's warm, a tingling resonance that reminds Zenitsu of a summer day. But most of all, it was a decidedly familiar tune. So kind and gentle that Zenitsu wanted to cry. He faced the source of the sound only to find the patient and beautiful ruby red eyes of Tanjirou Kanado, still decked out in demon slayer uniform, blinking back at him in curiosity. His mind chooses to run ahead without him. Wielding a pencil tip dipped in gold in one hand and violin bow emitting chirping birds with the other, words shape themselves in his head.

Please don't give up. I know it hurts but I promise it'll get better. I promise I'll be there for you.

It's him. It's his soulmate.

"Hey, the director asked you a question!" Inosuke interrupted Zenitsu's daze to march forward. He had a loud sound that reminded him of a stampede. About to get into the blond's face for trespassing, he's only held back by the plaid green arms of Tanjirou reprimanding him for being violent with strangers.

That was enough to kick start Zenitsu's common sense. Ripping his whiteboard from under his arm, he hurried to write his greeting in thick black marker and show it to the tallest of the three with a nervous tick in his brow. The awkward silence that stretched for the few seconds that it took for him to write caused a cold sweet to gather around his neck. He was so, so bad at this!

I am the manager for the band. I will be there to supervise the interview and collect information. It's nice to meet you.

The director smiled, finally understanding. Extending out a hand, Zenitsu hurried to shake it nervously. "Ah, well you should've said so before! I am very excited to hear what all of you can do. I am Sotozaki, and you are…?"

Zenitsu felt like kicking himself. That's right! He didn't even include his own name in his introduction.

Zenitsu Agatsuma

"I'm Tanjirou. It's a pleasure to work with you! Wow, you look like you're our age yet you're already so famous?" Zenitsu felt himself freeze when his soulmate dared to actually speak to him. His voice was soft as a cloud. Every sound coming from him was like the coming of spring. "That's really amazing. I'm actually a big fan."

Someone, a big fan of him...? Not of Itoka or Kaigaku? Zenitsu knew it was a roundabout implication. Of course Tanjirou was praising his siblings, but the thought was enough to have him feeling giddy. Taking his marker out again, Zenitsu is interrupted when the board-masked man of the three suddenly charges forward, headbutting him in the stomach. The force is enough to leave Zenitsu coughing, wheezing out soundless breaths.

Tanjirou is by his side in an instant. Zenitsu feels his heart sing at the warmth of the other's hand on his shoulder. "I-Inosuke!"

"I don't get this guy!" The boy in question exclaims. "He's pissing me off! Speak already, damn it! This is taking so long and I want to get on my food break!"

Zenitsu was a crier. He knew that. At the telltale sting of tears gathering in his eyes, he brushes Tanjirou off and races away from them before he can humiliate himself any further. He felt like such a baby, running away from his problems. Tanjirou would be so disappointed that he had such a horrible soulmate. Kaigaku would be so mad. Gramps would hit him. Maybe Itoka just wouldn't care.

He runs as far as he could to find at least one of his siblings. He spots Itoka first and like a lost cub, grabs her sleeve while she's in the middle of conversing with a confused Giyuu. She leans back, irritated. "What's wrong, Zenitsu? Sorry, this is my older brother."

What's wrong? What's wrong?! Everything…! How about the fact that it's almost time for their interview yet the only one who was actually there and waiting like he was supposed to was a hopeless mute who most likely already embarrassed himself in front of his soulmate?! What happened to how important this day was for them? They couldn't waste time.

Itoka only lets out a long-suffering sigh at his hand gestures. She clicks her tongue, raising a brow. "All right, all right. I get it. You can't handle yourself all alone." That line stings a little. It must show in his face because she goes to ruffle his hair in slight apology. "Seriously, Zen. You have to learn to grow up some day. I won't always be here to bail you out. We got to start setting boundaries for this kind of thing."

Zenitsu lowers his head, nodding. It still hurt.

"I know. I know. You're trying your best. You've gotten better since you started writing more music. I'm proud of you." She doesn't sound proud. Her music was more akin to the banging drums of Sakura-san when she started regarding Kaigaku as more trouble than he was worth. Still, she says her farewells to Giyuu and holds his hand while they make their way to the back of the studio. However, before they can take two steps, they freeze at the sight of hanafuda earrings blocking their way.

"Sorry," Tanjirou says sheepishly. "I came after you, Zenitsu, and kind of overheard everything."

Zenitsu wants to say that it's okay. That Tanjirou was such a kind person for caring about him but he couldn't possibly write any of that down in time before Itoka practically skipped forward, smile wide on her face. "It's no problem."

To his surprise, Tanjirou doesn't string along the conversation. Instead, he addresses the blond again by handing him a pen. "If something's bothering you or you need to say something, spin it in half a circle. We'll be sure to stop so you can talk. It works a lot for my siblings."

Zenitsu feels like crying. Tanjirou…! He was such a good person. Wait, he was his soulmate…! The infallible bond between them would surely conquer anything. Even Zenitsu's muteness, even past all of his insecurities and horrible social tact, and undoubtedly that small voice in his head that said that no one would ever truly be in love with him. Zenitsu was skeptical of all the stories that said that their connection would be strong enough to overcome all of that but now, staring back at Tanjirou's kind expression, he felt that small light of hope.

The song they would be performing was a challenge and a half. It had to encompass everything that Tanjirou's character was with nothing but sound and lyrics. As the scene itself was confirmed to be a fight, Kaigaku had suggested a more fast-tempo if not hard rock song. Itoka wanted something quiet and minimalistic. By the end of the meeting, the director left the kids scratching their heads.

The sister of the group eventually groaned, leaning back with a dramatic sigh. "I can't do this. I need to eat first." Zenitsu continued scribbling notes on his paper, deep in thought.

"You're always eating." Kaigaku quipped. Zenitsu shoved eraser shavings into the bin.

"Then it's settled! Time for food…!" Inosuke roared.

"Would you like anything, Zenitsu?"

The blond knew the voice well enough by now to recognize it as Tanjirou's. Still, he nearly ignored it by only giving a small shake of his head. The shuffling of chairs signaling everyone's departure was what permeated the room and as everyone left, Zenitsu could finally enjoy the peace and quiet.

"What did you think of the meeting?"

Zenitsu nearly jumped out of his seat. In his focus, he didn't notice that the ringing of the summer sky was still next to him. Tanjirou smiled and the blond wanted to melt. God, he was so pretty. He was so nice. Zenitsu felt like fainting on the spot at the ridiculousness of the situation. He was sure that he already had a massive crush on Tanjirou. Taking out his whiteboard again, he looked to Tanjirou just for the boy to nod in encouragement. Finally, Zenitsu scribbled out a few words.

I don't think my opinion really matters.

Tanjirou furrowed his brow at that. Of course he wouldn't like it. Zenitsu was already piecing together the notes in his head based off the absolute symphony that was playing from Tanjirou's soul. "It does. My character… in the show, I mean, has been through a lot. He lost his entire family. I don't know what I would ever do if that happened to me. If one more person is thinking of him even a little, he would really appreciate it. It would be like his family grew again stronger and better."

The blond squeezes the marker cap in his fingers, dumbfounded. Kaigaku and Itoka usually didn't like talking about these kinds of things. They were the ones who put passion into everything Zenitsu wrote. He was the one who had to worry about details like narrative and despair.

Do you think Tanjirou ever had problems showing his feelings? Like I do, Zenitsu doesn't add.

"Of course he does." Hanafuda earrings jingle like a bell. "If your band could help speak for him, I think that would be more than he could ever ask for."

Zenitsu felt the lid slipping from his fingers. The clang of it hitting the floor reverberates but his mind feels like an ocean. That was just it, wasn't it? Speaking for people who can't through music; encompassing everything that Tanjirou was and felt; declaring that he was here, that he was alive and still fighting for his sister. Zenitsu wanted to do that too. He wanted to talk. He could through his songs. His opinion did matter. And looking at Tanjirou, the actor, worriedly dust off the marker lid just to hand back to him, Zenitsu knew what the first thing he wanted to say would be.

I'm here. I'm your soulmate.

So Zenitsu absolutely drowns himself in the music and lyrics for the next few weeks. The song he has in mind already rings so profoundly in his head that it makes him want to cry. He sends snippets of what he hears from Tanjirou's sound to his soulmate almost every hour. He does it because he's here. He's Tanjirou's soulmate and he wants to scream it with his music as much as he can. As he plays the chord hundreds of times on his violin, changing it, revising it further, the picture of summer clears up in his head. Finally, it's complete. The final product doesn't come with rave reviews, but as the band comes together to practice their chords, the breathtaking masterpiece that Zenitsu created finally begins dawning on all of them.

"Damn." One of the boys whistles after hearing the final product.

Damn, indeed. With Itoka's singing accentuating each drop in the notes, the music is the absolute accumulation of everything that made Tanjirou the person he was. Gentle, kind, strong, but with demons that plagued his mind when no one was looking. It was a no-brainer what the name of the song would be: Tanjirou Kamado. Zenitsu felt his face heating up. It increased tenfold when everyone in the room looked at him funny after he signed it out. If his perception of Tanjirou from the show and the sound that he heard from the actor started blurring, that was his own little secret. What meant the most to him was that what he wanted to say was blared loud and clear through the final product, through the countless nights he spent sharing the same tune with his soulmate.

They send Zenitsu's message in the form of an email to the director, praying that their efforts came to fruition. The small group of friends cheers when it's finally over. As always, all of them barring Zenitsu opt to head out for the club in celebration. The blond retires to bed early, exhausted beyond belief as his ears feel like they're ringing from the constant use. His head also hurt. He felt like he hadn't had proper sleep in days. But through all of that, he did it. For the first time ever, Zenitsu felt like he finally talked to someone.

Please don't give up. I know it hurts but I promise it'll get better. I promise I'll be there for you.

He believed with all of his heart that Tanjirou would listen.

The ringing of the doorbell is what wakes Zenitsu up. He rubs his eyes from beneath his blankets and half-open notebooks piling on top. He's still sleepy. He can hear the creaking of the stairs evident that someone else went to get the door. There're voices muffled that he can't make out past the buzz in his ears. Seriously, his body hurt way too much! This was torture. There was no way he could be expected to rouse within the next two weeks! Still, his throat is parched and sometimes you had to make sacrifices.

Leaving the comfort of his own bed, Zenitsu trudges down to the living room not even half an hour after the doorbell rang. About to collect his water, he's instead tackled into the table by an excited Itoka.

"Zenitsu! Zenitsu, you won't believe it!" She squeals, hugging her brother tight. He chokes soundlessly where his chest hit the counter. "Your song! It was so amazing that the Tanjirou Kamado had to visit us to tell us himself. He said that my voice was incredible. He's never heard anything like it. When he first played it, he couldn't help but be taken by my singing. And. And-" She cuts herself off, her music ringing with a happiness that Zenitsu had never heard from her since becoming an orphan.

"He's my boyfriend now."

He isn't surprised when the next time he sees Tanjirou, the boy is emitting the sound of someone in love. Regardless of who his soulmate was, he truly saw the stars within Itoka. It was easy to understand. And Zenitsu didn't want to ruin that, not when his sibling and soulmate were so happy together. So again, he kept his mouth shut and didn't speak. He doesn't speak even as their band continued to rise in ranks for the next few years, winning competition after competition while capturing hearts. There are parties that Zenitsu doesn't attend. Interviews have him meandering in the back like a stalker as the world remained oblivious to his music. Through it all, he still refused to speak.

He can't bring himself to work up enough courage to attend their wedding though. That was crossing a line that he wasn't capable of going near. As he instead works himself to the bone within the covers of his room, he expects to hear grand stories about the chocolate fountain that Tanjirou had ordered, or about the horse and carriage meant to carry them off that they rented for the night.

Up until now, he'd been holding back all the negative emotions so that Itoka and Tanjirou wouldn't notice. But now…? By himself, he can feel whatever he wants. He can let out all of the sadness he's held his entire life and especially the past four years since they started this band where no one can see. He can vent and complain all he wants about the remnants of a broken promise. His head is filled with a dark sprawl of music that he creates and strums on his violin in order to cope. The notes come out as thunder. He has no friends, is worthless, riding off the coattails of his siblings, and rotting away in a pile of wealth and loneliness.

Caught up in his own despair, he doesn't consider how this soiled their connection or the person on the other side. He doesn't consider, doesn't understand the true depth of which a soulmate's psyche could affect the other. So when Zenitsu wakes the next day, the day of the honeymoon, only for Kaigaku to burst in his room screaming, Zenitsu can only cower in the corner while sobbing about why his brother was so angry. When words finally register, a mixture of phrases like `Tanjirou` and `jumped off the roof` hit him like a freight train.

Zenitsu talked. He talked a lot, but he never tried to speak again.