Summary: This is certainly the hardest thing Inosuke has ever done. Acting civilized for more than a few minutes was already a task, but a few hours?! …It is Nezuko's and Zenitsu's wedding, after all, and if Tanjirou asked him to… he'll try his best.

Gateways to the Heart

Tanjirou was in tears when he first saw his sister in the white kimono walking side-by-side with Zenitsu – of this, Inosuke was well-aware. Nezuko's matching white headdress, traditionally used to hide the horns of one's demonic qualities, held quite a different meaning for her. With Zenitsu's bright golden hair glistening especially against his black kimono and grey hakama, the steps of their zōri were quiet as they walked through the orange gates. Inosuke was behind the three of them, feeling itchy in the blue-grey kimono he'd been stuffed into earlier, completely against his will. He was doing his best not to cause a ruckus, sensing this event to be of some great significance, but he was sweating worse than normal, and he could hardly breathe. He wanted to tear the thing to shreds.

Behind Tanjirou in the procession through the shrine, Inosuke could sense his friend's vacillating emotions through the ground with his heightened sense of touch. With every step, Tanjirou's normally calm and rooted steps trembled, as if at any moment, he would collapse. Tanjirou swelled with relief, pride, mourning and disbelief all at the same time. Not knowing what to make of the entire procedure, Inosuke went along with Tanjirou's request to wear this thing and remain civilized – not without voicing his rejection of the idea.

"There's no way I can take this!" he'd protested in the changing room. It was ten minutes before the start of the ceremony, and he was doing everything he could to dodge Tanjirou's arms. "That thing is way too stifling – I'll die if I have to wear that longer than a few seconds, forget a few hours!" The bulbous blue eyes of his boar head shone opaquely in the afternoon light seeping through the windows, panicked and agitated.

Normally accepting of Inosuke's animalistic nature and crudeness, Tanjirou had been chasing Inosuke around the room for nearly an hour trying to get him to keep the heavy clothing on for more than a few seconds. Knocking over paper walls, causing vials of makeup to crash into the ground, and bumping into the groom more than once while applying powder to his face, Zenitsu looked on in blasé concern. Finally, when Tanjirou had caught the man-boar's fur-covered legs, causing him to topple over and squeal like a – you get the point – Tanjirou had been desperate. His voice was thick with the frustration and woe he had held back for the last sixty minutes. "Inosuke, please! This is really important to us!"

Almost in tears, Inosuke had felt something in his friend's plea that he had scarcely felt in Tanjirou before. The young man's hanafuda earrings jerked as he leaned over Inosuke, imploring. "If you don't do this, then Zenitsu's…! Then Nezuko's…!" He was at a loss for words, his faded right eye outshining the left.

Five years had passed since they defeated Kibutsuji Muzan together, and yet something about his friend seemed as desperate as back then. Whatever Zenitsu and the once-demon-now-human-girl hoped to do was important… wasn't it?

Inosuke's boar head had stared at Tanjirou in shock, frozen. After that, he begrudgingly complied with Tanjirou's request, and allowed himself to be dressed in the stuffy clothing, fidgeting the entire time and trying to loosen the collar whenever he could. Unmasked and unable to move as freely, seeing Inosuke's beautiful, if disgruntled features, Tanjirou stood back and smiled at him, causing Inosuke to pause in his fidgeting. Even Zenitsu's expression softened as he looked on in the background. "There. Now you're ready."

He'd blinked confusedly at that.

Inosuke definitely hated this thing. Even now, sitting on a cushion in the front row a few feet before Nezuko and Zenitsu, who sat before the Shinto priest and shrine maiden and took their san-san-kudo vows, Inosuke felt like he could scream at any moment, ripping the individual threads of the thing around him without remorse. How he wanted to…

But he wouldn't.

The look on Tanjirou's face when he had stepped back and seen Inosuke in the full kimono and hakama; the feeling emanating from his friend now as he passed the three cups of saké to Nezuko and Zenitsu. Inosuke had to admit it was… endearing.

Now, Tanjirou was sad, yet bursting with elation.

Why…?

It wasn't much longer after that the newly-wed couple pranced out of the shrine, a glow in their eyes as they grasped each other's hand, the former Hashira and Kakushi not far behind. Their jubilance and glee radiated from every corner of the shrine as they passed back through the spirit gateways, into a new stage of life.

He was happy for their happiness, still… Inosuke couldn't understand it at all.

. . .

That night, the afterparty in the private room of the teahouse consisted of drinks all around. The former Demon Slayer Corps members were making quite a riot in the teahouse – especially Sanemi and Genya, who, drunk off their asses, couldn't stop getting into disagreements over which one of them had the more aesthetically-pleasing scar on their face. Uzui Tengen and his harem of Makio, Suma, and Hinatsuru bellowed out laughter and obscenities together as they downed drink after drink of saké, while Shinobu sat uncomfortably close to Giyuu Tomioka, cup in hand, egging on every part of his short temper she could get her silky hands on. His tongue was looser on drink, and nearly every vein in his head looked about to pop as he sipped from his cup, doing his best – and failing valiantly – to ignore Shinobu. Himejima Gyomei sat as statue-like as always, listening attentively to the atmosphere around him and Rengoku Kyojuro, who he spoke boldly about his current and future endeavors, appreciative of the good food, almost completely unaffected by the alcohol. As usual, Muichiro looked zoned out and dissociated from everything that was happening around him.

Apart from the emotions of the former Hashiras running high, in another room connected to but separate from them, Nezuko, Zenitsu, Tanjirou, and Kanao chatted amongst each other, along with Aoi, Kiyo, Sumi, Naho, and the former Kakushi. Inosuke was among them, but uncharacteristically quiet and dazed throughout the meal and conversation afterward. It wasn't until halfway through the night that, with gritted teeth and after much booze, Inosuke leaned over to ask Tanjirou whether he could change back into something more comfortable. Tanjirou, blanching, realizing how long his friend had been bearing the discomfort, immediately apologized for his mindlessness and – much to Inosuke's relief – said that he could go take it off.

Stumbling out one of the sliding doors of the teahouse and into the gardens of the courtyard, Inosuke shut the door behind him, blocking out the din of the party. Too exhausted from having to wear the kimono and hakama in the shrine and crowded teahouse for over six hours, Inosuke's pupils were empty as he slumped to the ground. The front of his yukata was open to show his bare chest, with the sleeves rolled up over his shoulders, the bottom hiked up to the tops of his thighs. The cool night air felt good on his damp skin. He took in the sound of the running stream and bamboo hitting the fountain basin throughout the gardens, privy to the noise behind him, such silence was unbecoming of him.

Something made him hesitant to go back inside. Green irises mulled over the immaculate gardens. Lips slightly open, deep in thought, Inosuke couldn't quite grasp what it was. Five years had passed. Even after defeating Douma and remembering his mother and her sacrifice, Inosuke had a lot of difficulty adjusting to normal life in society. He spent most of his time with Tanjirou, Zenitsu, and the other former Demon Slayer Corps members, who knew and understood him, but they all acted so weird sometimes. With everyone trying to adjust to a normal life in modern Japan, they wanted to fit in so much to the point that it just annoyed Inosuke.

Today was a whole new level.

Back inside one of the party rooms, Tanjirou noticed Inosuke had been gone for a while, more than half an hour. Changing from a kimono and hakama into a yukata didn't take that long, and normally, the piggish man enjoyed the liveliness of parties more than anybody. The fact that he hadn't returned began to worry him. Standing from the table, he told Nezuko, Zenitsu, Kanao, and the others, "Hold on, I'm going to go find Inosuke." Nezuko nodded in understanding.

It wasn't long before he discovered the lone shadow of the figure sitting on the edge of the verandah outside in the courtyard. As if he had sneezed and known Inosuke was having a mental conversation about him outside, the door slid open. Inosuke jolted out of his thoughts.

"Who's there?!" he yelled demandingly. He stood on the wooden verandah with his hands raised defensively, only to see Tanjirou's calm smile. Half-turning his head away, scoffing slightly, Inosuke slumped back down on the verandah's edge, grumbling. "Oh. It's just you."

Sitting beside him, Tanjirou brought his feet to the edge of the verandah, letting them hang over. "It's strange to see you outside by yourself, Inosuke." His smile was as blindingly foolish as ever in the moonlight, tone light and sweet. Inosuke tried not to let it get to him – in more ways than one.

"Yeah? What's so strange about it?" he asked in a confrontational tone, though he still didn't look his friend in the eye.

Tanjirou's dreamy eyes reflected the white light of the moon and twinkling stars amidst layers of auburn, if faded, his face turned up toward the sky. "Normally, you like being in the middle of all the commotion, but tonight you left faster than I could follow you." His dark hair was long enough to be kept back in a ponytail again, where it stayed now, in respect for the occasion.

"It's because you made me wear those stupid clothes!" Inosuke accused. His beautifully feminine face was suddenly close to Tanjirou's surprised one, unable to keep his anger contained any longer. His face went red with annoyance and embarrassment.

A mere few inches from Inosuke now, Tanjirou blinked a few times before he smiled again. "Thank you for dealing with it all day. You did a great job."

Further irritated by how warm he felt from Tanjirou's praise, Inosuke hit him on the head.

"Oww, what was that for?" Tanjirou whined, eyes watering as he rubbed the wound – too close to the scar on the left side of his forehead.

Blushing, Inosuke spluttered, "N-nothing! It's f-for being a little bitch!"

Tanjirou pouted exaggeratedly at him, but when he saw Inosuke's thorough avoidance, he knew what his friend really wanted to say. Tanjirou found it cute, knowing he could make his friend react in such a way with the simplest acts of affection. He was sure Inosuke would hit him on the head thrice as hard if he could hear his thoughts right now, but Tanjirou sympathized with his situation. The Demon Slayer Corps was disbanded. Everyone had begun to fall into their own rhythms of life – by getting married, or finding new hobbies – but not Inosuke. Having grown up alone in the forest amongst only boars, Tanjirou could only imagine what his friend must be feeling to have that level of freedom taken away. Hardly coming into contact with anybody, then being thrust into the conflict against Kibutsuji Muzan, only for it to be over within a matter of months. Everyone was trying to embrace the new modern era now that the demons were finally eradicated, but for Inosuke, a normal life in Japanese society held no meaning.

Sure enough, reeling around to see Tanjirou's tender stare, Inosuke raised his fist threateningly. "Wh-what are you looking at?!"

"I know you've been having a really hard time adjusting, Inosuke," Tanjirou acknowledged sincerely, ignoring Inosuke's threatening demeanor. This caught him off-guard, and his fist lowered again in shock. When Tanjirou didn't say anything else, Inosuke planted his hands between his spread legs. His shoulders scrunched up as he muttered to himself like a pouty kid.

"Yeah, I mean, what was with all that today, huh?! Your sister and Zenitsu – and everyone else – acting so pretentious and showing off – why was it such a big deal?!"

Inosuke went on without pause, until Tanjirou had no idea what he was going on about. Eventually, thinking Inosuke didn't understand what he had been a part of today, he cut in where he thought was most appropriate. "That's because Nezuko and Zenitsu got married!" Tanjirou exclaimed. His heart felt like it wanted to burst just saying it, and he could hardly contain his smile, arms spread wide.

Instead, Inosuke just felt more frustrated. "So what?!" he blurted, unable to stop himself. "What's with all the fuss?! Can't two people just be together?! Why do they need to make it so public?!"

"Because it's a wedding!" Tanjirou replied, equally as passionate, but not nearly as annoyed as his friend. "A wedding is when two people want to make it official enough for everyone else to see! Isn't that wonderful~?"

Throwing his head aside, Inosuke's black hair flicked across the shoulders of his yukata. He harrumphed with his arms crossed. "Uhg, who cares! I just want Gonpachiro to be with me forever! Who cares about making it official?!"

In the silence of the gardens, there was a beat of bamboo hitting stone where Tanjirou could hardly believe what he just heard. When he realized Inosuke's frustrated and exasperated mood hadn't changed in the slightest, not looking at Tanjirou in his impatience, Tanjirou knew his friend had no idea what he said.

He burst out laughing.

"What's so funny?!" Inosuke swooped on him like a hawk, those intense green eyes boring into him. "It's the truth!"

Tanjirou only felt he was losing himself even more as he clutched his stomach, rolling over.

"Hey! I mean it, Tontaro! What's so –?!"

Right then, the sliding door flipped open. A drunk-as-balls Kanroji clung to the arm of Iguro, hardly able to stand. "Tanjurou! D'ere you are!" the pink-haired lady slurred, swaying like a tree in a storm even as she held onto Iguro's arm. "Nezuko wuz looking fer ya – she said Zenitsu and Kanao got out of hand trying to out-drink each other… I think you better come come quick."

Wiping the tears of joy from his eyes, Tanjirou sat up to address her, only causing Inosuke to get more annoyed. "Thank you, Kanroji-san. Please tell Nezuko I'll be back inside in a minute. Hey, Iguro-san."

"Hey. I better get her back inside before she falls over right here and now. If you'll excuse me." Kanroji gave them a thumbs-up, humming wondrously to herself as Iguro nudged her back inside.

Continuing right from where they left off before being interrupted, Inosuke pointed after them as he said, "That woman and the snake, too! They had a whole ceremony and for what?! They didn't even need to! Everyone knew they were already together!"

"Inosuke –"

Before Tanjirou could say anything, Inosuke turned back to the gardens and crossed his arms and legs, roaring in frustration. "I don't get it! All this stuff seems like pointless threatrics to me!"

Taking note of his stubbornness, Tanjirou knew that explanations weren't what Inosuke wanted to hear right now. Frankly, what could he say, knowing that marriage between him and Tanjirou…? That two men…? It wasn't allowed.

"Inosuke," Tanjirou started again. Eventually, the boy he had grown up with these last five years, now a young man, looked back at him. "You're right. It doesn't need to be made official for everyone to know. But sometimes…" Tanjirou wasn't sure where he was going with this, even as he reached out a hand toward Inosuke's face. Midway there, he stopped, his fingers curling. "Sometimes it's nice, you know?"

Inosuke watched him, dumbfounded. What is he talking about? Again, through his sensitive sense of touch, Inosuke felt Tanjirou's heart beating in a peculiar way, different from that afternoon – and he wondered, Can he smell something strange in my aroma as well?

Nothing more was said on the matter, for then Tanjirou unceremoniously stood from the verandah, walked back toward the sliding door. "I'm going back inside to check on Nezuko and the others. I hope you'll come back and join us too."

There was that warm smile again, but something about it was strained as he disappeared through the door, closing it behind him.

Now only more confused than before, Inosuke ran his hands through his blue-tipped hair in dissatisfaction. "Raaaagh! What the hell?!" He laid back against the wooden planks of the verandah, staring up at the stars. Everything had gotten louder inside the teahouse, somehow, but it felt even more distant to Inosuke. He recalled the orange gates they had traversed through earlier that day, while Tanjirou struggled to hold back tears. Long ago, Inosuke remembered being told those gates were entryways into the spirit world, a place that marked where the mundane turned into the sacred.

What could he have meant by that?

"But sometimes… Sometimes it's nice, you know?"

He'd never seen Inosuke look that ancient and nostalgic at the same time.

"I don't get it," Inosuke yawned aloud, his eyelids heavy as he remained lying down on the verandah.

As Tanjirou tried to get Zenitsu to climb off the table, where he bellowed love ballads to Nezuko on one knee of his hakama, her face red from affection and humiliation, Inosuke drifted to sleep. He dreamt of the time he would be able to float into Tanjirou's arms without restraint, opening the gateway to his own heart.

This is my second commission for the lovely Tiburme on Tumblr! (Please check out her art guys she's so talented and her style is so somft I die…) Even though I thought InoTan was cute before this, I hadn't thought too hard about how their dynamic would work until now. I decided to make most of the fic from Inosuke's perspective, since Tanjirou is the kind of sweetheart who likes everybody and would be easier to understand. As for Inosuke… he a blockhead. So I wanted to understand things from his PoV~

I really liked the splash of reality I was able to add in this fic despite it being an AU (you can pry Rengoku from my cold, dead hands). The cultural embeddedness of Demon Slayer is something I really adore. I'm so thankful Tibu and I parsed out this idea together! Bless you, bro! ;;c;;

My commissions are still open if anyone is interested btw, so hmu over PM if you have any questions!

I could definitely write another chapter or two of this…! Tell me your thoughts below!