Work Header

Declarations of War

Work Text:

Inosuke thinks Monjirou and Bonnitsu are dating.


Inosuke knows they are dating, especially after he had to ask Aoi what “dating” meant and why the losers in school kept making fun of them for “dating”.


The first time Inosuke had noticed had been when he was about to skip class. At least until he realized it was Professor Sanemi’s class, and if he missed it then—well, Inosuke isn’t sure what would happen, but he doesn’t want to find out. Kammitsu’s screams last time he got in trouble with Sanemi was enough to deter him from doing such – even if Kammitsu is the biggest wimp ever.


Anyways, Inosuke was rushing to her class, tempura in hand when some random said, “Apparently, Tanjirou and Zenitsu are dating—” and Inosuke had stopped right in his tracks, almost running into a locker. The random girl and her friend hadn’t noticed him yet—and Inosuke was three seconds away from throwing something at them. For some reason, people liked saying mean things behind their backs but not in front of their faces. Luckily for Konjirou and Monitsu, Inosuke will defend them (because they’re too nice/weak to defend themselves).


“Don’t you weaklings have anything better to do?! Monjirou and Bonitsu aren’t dating so stop insulting them!” The girls screeched, breaking into a run. Inosuke would chase after them but bell cuts off any thought of giving chase. Professor Sanemi is going to kill him.


She doesn’t kill him, but Inosuke does have to go to the medical center with a comically large bump on his head. Kanjirou is next to him, the redhead trying to “console Inosuke because it looked like it hurt” but it definitely doesn’t hurt, the water in his eyes is because Inosuke wants to make fun of Bommitsu alright?! Speaking of the idiot, Inosuke turns around, throwing his bag at the blonde. Kammitsu screeches like a banshee, and Inosuke blocks his ears reflexively because damn if Monitsu wasn’t such a loser, he could probably become a singer.


“Why were you late Inosuke, I thought we told you to come early,” a hand on his shoulder distracts him, Inosuke turning to face Monjirou. The other’s worrying his lip, sadness clouding his eyes. Inosuke bristles, he dislikes seeing Monjirou sad because it makes Monjirou look like a weakling. And Inosuke isn’t friends with losers (except for Bonitsu, but that’s only because Bonitsu is friends with Monjirou).


“I was protecting you weaklings!” His chest puffs out, Inosuke beaming with pride. Bonitsu mumbles on the side, going on about how, “he doesn’t need protection, and the only one that needs protection is Inosuke” but that’s a load of nonsense. Tanjirou smiles, patting his shoulder again.


“Some loser said you two were “dating”, and I told them to stop saying stupid shit!” At his words, Tanjirou’s smile falls, the hand on Inosuke’s shoulder gripping harder. Monitsu is the one that breaks the sudden silence, a frown on his face:


“Is there a problem with me dating Tanjirou?!” His face is filled with anger and disappointment, a stark contrast to the whimpering mess he typically is. For a few seconds, Inosuke’s filled with shock—it must be a trick on his eyes. Monitsu? Intimidating? Perish the thought.


Inosuke shrugs, rubbing the bump on his head, “Isn’t being called a “dating” a bad thing…” Inosuke doesn’t get to finish, Monitsu breaking into laughter, his anger dissolving into nothingness. Inosuke responds by hurling his bag at Bammitsu, the idiot screaming and diving out of the way.


“Dating isn’t a bad thing Inosuke,” Monjirou has a loopy smile on his face, “it’s a thing people do when they like each other a lot.”. Inosuke frowns, turning to Monjirou (Inosuke doesn’t notice that he almost hits the door, but Zenitsu opens it in time).


“Are you saying you don’t like me?! I want to be a “dating” as well! It sounds awesome and I’m awesome,” Bonjirou sputters, a blush growing on his face. Monitsu screeches again, and when Inosuke responds with a kick in the head the idiot still refuses to go silent.


“You can’t just say that!” There’s a finger in his face, Bammitsu yelling as usual.


“The Great Inosuke will say whatever he wants!”


“The Great Inosuke will lie down or else…” It’s Doctor Shinobu, a smile yet not a smile imprinted on her face. She’s seated on a swivel chair, pointing at the bed for Inosuke to lie on. “Sanemi did a number on you, didn’t he?” She hums pleasantly, tuning out their bickering. It takes less than a minute before she’s sending them out, telling them not to return for the rest of the day or Zenitsu’s gun access will be limited.


Whatever that means.




Inosuke thinks Monjirou and Bomitsu are getting bullied.


Inosuke knows Monjirou and Bomitsu are getting bullied. One day, Bonitsu came to school with blood on his shoes. Inosuke’s no idiot, and he noticed it instantly, but everyone brushed it off like it was no big deal. Even Kurata – Bomitsu’s other friend—brushed it off like it wasn’t a big deal. The blood on his shoe was obviously a sign that someone must’ve injured Kammitsu, but Kurata looked at him like he was crazy.


“Bos-- Zenitsu? Injured? That’s the funniest thing ever. He’s showing off to Tanjirou, that’s what he’s doing.” Inosuke stared at Kurata for a few seconds before hitting the idiot on the head. “Ow—if you weren’t with Zenitsu I’d totally beat you!”. Inosuke just turned and left, tired of Kurata’s nonsense.


Even Monjirou says nothing about it, instead blushing again! Why?! Inosuke nearly flips the table in irritation. “Monitsu’s injured!” Monjirou stops smiling, a frown growing on his face. Bonitsu screeches again, flailing.


“Tanjirouu—he’s lying, don’t believe him! I definitely didn’t get injured.” Bonitsu pouts, glaring at Inosuke.


“Do you wanna fight you weakling?!”


“I’m not a weakling—Tanjirou defend my honor!” The redhead just laughs, before reaching out and grabbing both of their hands.


“Stop fighting, please.” They don’t stop immediately. But they do stop, just a little. Sometimes Inosuke has to make his minions happy.


Inosuke forgets the blood on Monitsu’s shoe. It’s the next day – he comes way, way earlier to school because the karate club is holding a meeting. He likes the karate club. Inosuke is about to open the door, when out of the corner of his eye, he catches a weirdo going through Monitsu’s locker.


“Hey! What are you doing you weirdo?!” The thief starts running before Inosuke finishes – and Inosuke loves being right, he knew they were getting bullied. As usual, it’s up to Inosuke to protect them.


He chases the person down, running through hallways, jumping over lockers the idiot keeps pushing down.


They’re no longer in school, Inosuke still giving chase. The loser turns round the corner, and Inosuke turns round as well—


A boot to the stomach sends him flying to the ground. Gasping, he turns, narrowly avoiding a fist – but Inosuke doesn’t avoid the boot that presses down on his leg, bending it at a weird angle. “Fuckers—” a kick to the mouth cuts him off, Inosuke hissing.


Turning his waist around, Inosuke grabs at the person stepping on him, pulling them down for a headbutt. It hurts—his head stings and starts to throb. Shit his forehead isn’t as strong as Monjirou’s! Inosuke manages to hold the person in a slight chokehold, but then another leg is kicking him. There’s more than one person. His vision is slightly bleary, multiple feet trying to kick him. Inosuke uses the person he’s holding as a shield, yet the attackers still hit him.


Damn it all. Two hands grip his, pulling him off the meatshield. They twist him onto the ground, Inosuke grunting. There’s the sound of shoes clicking on the floor and then he’s getting kicked in the face. Again.


“Tell Tanjirou the Spider clan says hi.” The person speaking is small – Inosuke can barely make that out—and their hair is a starch white. And… they’re kind of ugly.


“You’re ugly.” Inosuke lets them know. Their face twists, a snarl instead of their fake smile.


“I change my mind. Father, break this mongrel’s arm.” Inosuke frowns, about to retort but there’s a crack and his arm burns—


He screams.


The people leave soon after. Inosuke’s still on the ground, groaning. He knows he should go to the medical center first, but Inosuke had promised Monjirou he wouldn’t come late. So, Inosuke eventually pushes himself off the floor and walks back to school.



His arm aches. It’s a distant ache, the kind that if he wills himself not to think about it will go away. Eventually.


Inosuke kicks open the door, grin on his face. “The Great Inosuke is here!”.


Nobody is smiling.


Kurata’s dumb face is agape in horror and shock; Inosuke turns to face Monjirou—and holy shit, he’s smoking—Inosuke blinks once and Konjirou’s up, table pushed back with force Inosuke’s never seen before; Tanjirou takes two large strides to Inosuke and Inosuke flinches—


Why the fuck did he flinch? Inosuke doesn’t get to question it further, Tanjirou gripping his hand (and promptly cursing when Inosuke lets out the smallest yelp) and suddenly he’s getting yanked out of class.


The teacher obviously tries to complain, but Zenitsu stands up with unbridled fury—


Shut up.”


The teacher shuts up almost instantly, mouth opening and closing like a gaping fish; Inosuke doesn’t get to see more because Tanjirou slams the door close.


“Monjirou—” Tanjirou interrupts him, pushing Inosuke into the next classroom. It’s empty—how Tanjirou knows that is beyond him—and there’s a hand on his chin, tilting it down. It’s Zenitsu that’s touching him; Inosuke turns to face the other boy and Tanjirou delicately thumbs the blood off his lip.


It’s quiet, Inosuke wants to say something but nothing seems to come out. Tanjirou holds his thumb out, like it’s something marvelous and for a beat, nobody says anything. Zenitsu looks him dead in the eye, grip on his chin getting tighter. Inosuke’s heart jumps—nope, he’s gotta end this now.


“Bonitsu, what are you—”


Who did this?” Zenitsu’s voice is quiet and tense, his anger barely restrained.


“Let go—”


“He asked a question Inosuke. Answer. It.” Tanjirou cradles Inosuke’s injured arm like it’s the most precious thing in the world.


“It’s the Spider clan? Spider losers if you ask me.” Zenitsu’s eyes narrow, sharing a matching grin with Tanjirou.


“Good job Inosuke,” Zenitsu smiles at Inosuke, patting him down. Tanjirou presses his lips to Inosuke’s knuckles—


“Why are you trying to eat my hand Kanjirou?!” He tries to move back, but Tanjirou and Zenitsu’s grip doesn’t let him leave.


“Tanjirou will take you to Shinobu. I’ll deal with this declaration of war.” Zenitsu finally let’s go of his chin, and steps back. Tanjirou takes the opportunity to lift Inosuke clean off his feet, which sends Inosuke into another fit.


“What do you mean declaration of war?! Put me down Monjirou!” Tanjirou refuses to let go, even after Inosuke hits Tanjirou’s back with his good hand.


“It means I’m going to kill them. With guns.” Tanjirou talks slowly, almost as if Inosuke’s an idiot. Which he’s not, thank you very much.




It’s Zenitsu that turns around, almost incredulous. “This is the mafia. Of course, we’re going to use guns. Especially if they hurt my people.”


Inosuke pauses on Tanjirou’s back, thinking. “Can I use a gun? I want to use a gun!”


“Aw, that’s so cute—of course you can Inosuke. After we beat Rui and his gang into the ground.” Inosuke doesn’t struggle anymore when Tanjirou takes him to the medical center. Shinobu doesn’t even bat an eye when they come in, instead muttering about “declarations of war and possessiveness”.


No one says anything when Zenitsu and Tanjirou walk in the next day with blood staining their shirts.