Welcome to silliness! This is a ridiculous crack badbadbathhouse fill (prompt being: Souji is a stealth grammar nazi, finally cracking under a specific common error). Approach at your own discretion. :/
It's also fairly old, so forgive less-than-perfect writing as well. Given the title, I find that to be painfully ironic.
Souji Seta is a boy who prides himself on doing things right.
He gets up every morning, brushes his teeth, and always remembers to floss. He never has a hair out of place, his clothes are never wrinkled, and his shoes have a mirror-like quality that only comes with hours of dutiful polishing. His homework gets checked thrice each night before being tucked carefully into his schoolbag and, when he pulls it out in class the next day, it is unfailingly crease-free.
His loyalty to perfection, however, failed to rub off on his friends.
Chie -- dear, innocent Chie -- was one of the worst offenders. With scabby, grass stained knees, tousled hair, and the pungent smell of sweat wafting from her person she stood in stark contrast to her sparring partner (whose suit jacket and ironed slacks seemed decidedly inappropriate for the occasion). They'd been at it for hours, going over katas and the best way to knock an enemy flat on their back. Well, really, Chie had been going at it for hours while Souji played the role of The Enemy. Unfortunately, without something to swing, his defense usually consisted of raising his hands over his face just before the blow impacted.
With a well placed kick to the side, Souji was once again sprawled over the muddy ground of the flood plain.
"C'mon, you been practicing at all?" Chie laughed, hopping from foot to foot like some bioengineered rabbit.
No. Rolling around in the mud isn't really my thing. And it's 'have you been'.
"Not enough, apparently," Souji offered with an easy smile, trying to scrub out the Galapagos Island shaped stain on his pant leg, "I'm exhausted. Why don't we call it a day?"
"Already?" There was a pout in her voice but the adrenaline kept a broad grin plastered across her face despite it, "We've only been at it since eleven!"
Souji glanced down at his watch. It had stopped at three o'clock. Key word being 'stopped'. He'd need to make another trip to Junes jewelry department to get it fixed. The attendant knew him by name at this point and, regrettably, that meant she got chatty. If he had to hear another verb/subject disagreement he was going to kill himself.
"I know!" Chie announced brightly, "Let's go to Junes! I'm starving!"
There's a bit of steak between your teeth, so I can't imagine how. …Unless it's been there for a while. Augh.
"C'mon, it'll be on me~!" she chirped, hooking her friend by the arm, "I owe it to ya after beating you up so bad."
"Alright," Souji managed after a few moments, biting the inside of his cheek to keep from commenting on her incorrect use of the word "bad", among other errors, "Let's make it short, though, alright?"
"Huh?" Chie asked, looking up from the phone she had just been animatedly texting from. Almost instantly, a wide and somewhat…guilty smile spread across her face, "Oh, yeah, sure!"
Souji's fearful suspicions were confirmed when the two arrived at the Junes food court only to be greeted with the faces of the entire Investigation Team (sub Yosuke; although he probably wasn't far off). Chie ran ahead, snagging a seat next to Yukiko while the two girls started chatting animatedly. Souji hung back a moment to steel his nerves. He was good at keeping up a happy face for his friends most of the time, but it hadn't been a lie when he told Chie how tired he was. And when Souji got tired, the edges of his perfect self started to fray slightly.
And when Souji started to fray…
"Heya, Senpai!" Kanji greeted robustly, pulling out a chair with a little too much force, "Don't just stand there, siddown and stay a while, why dontcha?" If Souji winced, no one seemed to notice.
"Thanks," he smiled, taking the offered chair between Kanji and Naoto. The latter sat to his left and sipped taciturnly on her soda. At least she wasn't going to be adding to his headache.
"Thanks for inviting all of us, Chie-senpai!" Rise chirped happily. Chie flashed Souji an apologetic grin, although the bubbly idol didn't seem to catch it, "I'm glad I had an excuse to get out of the shop. This customer that I was serving just would not shut up!"
Souji's hand found its way to the table's edge, tightening ever so slightly.
"Oh, me too, Rise-chan," Yukiko added, smiling gratefully at Chie, "I kept getting drug around from room to room before that text saved me."
His knuckles turned white.
"I wasn't doin' too good either," Kanji offered around a mouthful of takoyaki, "You're a lifesaver, Chie-senpai!"
It's okay, Seta. Just ride it out. You can do this.
"Ah ha, it was no problem," Chie laughed nervously, keeping one eye trained on Souji's face. It had taken on a decidedly red hue. "So, where'd Yosuke n' Teddie get to?"
"Bear-da!" a voice twinkled from behind them, accompanied by a soft squeak squeak. The group turned around to see Teddie and Yosuke approaching in their Junes uniforms (although the latter nearly had his off).
"Man, I thought break would never get here," the redhead whined, finally freeing his arms from the straps of his apron, "Hey guys!" He stopped behind Souji, clapping his best friend on the shoulder. The boy in question tensed visibly.
Just keep calm, Seta.
"So, what's up anyways?"
In retrospect, Souji realized that what happened next might have not been exactly fair to his friends. They didn't know of the thrill he got when he witnessed a well placed comma or how his heart would flutter with every correct usage of the word 'whom'. They didn't know about his favorite tome, The Blue Book of Grammar and Punctuation, whose pages he would lovingly turn each night before bed. They didn't know that then…although they were about to learn.
He stood up with enough force to make the table shake. All faces (at their table and otherwise) snapped to him in shock and a little fear. Souji's face resembled a plum.
"Anyways!" he roared, turning on his best friend, who merely whimpered in response, "Isn't grammatically correct. None of the things you idiots say are grammatically correct! Or should I say 'is'? Would that make more sense to you!?"
You could hear a pin drop.
"You," Souji started, turning back to Chie, "You like that word, huh? 'You'? You like it a lot, don't you!?" His friend merely gaped. "You like it so much you seem to want it to get the spotlight in every sentence you make! If you can call them sentences! 'Souji, you want to go somewhere?' 'You doing alright, Souji?' Oh yeah, 'you' is a fucking star!"
"I…," she started, not understanding a word.
"How about words like 'do', 'have', and 'are'? Are you not on good terms with them? Because, damn, you sure seem to avoid them like the plague!"
"Hey-," Yukiko frowned, starting in on her friends defense. She didn't get far, though.
"Yukiko!" Souji smiled -- a wide, disturbing smile -- before turning to face her, "How are you doing? Are you okay?"
Taken aback by the sudden sweetness, Yukiko merely stared.
"Ah, not too well, I see. I can understand. I can't imagine what it's like to get drug around. Which hurt worse, getting shot full of chemicals or shoved into capsule form?"
The red-clad girl had never looked more lost, which was definitely saying something. Souji showed no sign of stopping to explain anything to her.
"You know why I can't imagine it, Yukiko? Because it can't happen! You get dragged. You can't get 'drug' anymore than you can get 'hat'. The only drug you're on, Yukiko, is laughing gas!"
Kanji stood up next, while Yukiko took a moment to recover from that last slap in the face. Gripping the table with rage, Kanji could barely control the tone of his voice when he started speaking, "The hell's with you, man!?"
"The hell is with me, Kanji? I hadn't noticed."
"See, that's just it. Do you take no pride in how you speak, Kanji!? I mean honestly? Every time you bust out another 'good' or 'somethin'', I want to gouge my eardrums with a rusty screw driver just so I don't have to listen to the screams of your sentence structure being murdered in front of me!"
"Well if that's how you felt, why didn't you say somethin'!?"
Souji tangled his fingers in his hair, gritting his teeth as he let out a particularly aggrieved groan.
"Woah, partner, woah," Yosuke began, squeezing his friend's shoulders, "I think maybe you need to sit down a bit. Maybe take a breath. You seem a little tense."
"Oh, I seem a little tense, huh?" Souji shot back mildly, not taking his eyes off the tabletop.
"Yeah, just a little, man!" Yosuke laughed awkwardly, trying to ease him back into the chair. Unfortunately, Souji had other plans, and snapped out of his friend's grip violently.
"You know what's making me tense?" Souji asked, eyes fixed on Yosuke's while the redhead simply gaped, "You really want to know what's making me tense?" Souji was digging through his pocket now, pulling out a shiny black phone.
"Uh, partner, remember that thing about taking a breath…?" Yosuke began, backing up slightly.
"Sji Y dnt U cum ovr 2sday?" Souji read, pronouncing it as phonetically as was possible, "What exactly were you asking me here, friend?" Yosuke went red in the face, trying to grab the phone from his friend's hand.
"Shut up, you idiot!" he hissed, trying to jump at the phone where Souji had moved it out of his reach.
"You should really watch your spelling. People might get the wrong idea, if they read this…"
"I said shut up!" Yosuke shouted, fists balled by his sides angrily. Souji was about to read another (less clean) message before Rise stood up behind him, hands poised furiously on her hips.
"Souji-senpai, that is enough!" she squeaked, glaring at him dangerously, "You can't just yell at people like this! We have feelings!"
"Oh, I know all about your feelings, Rise." Souji made a big show of cycling through his phone to get to her texts, "You communicate them all so well. Tell me, what sort of emotion does backslash-parentheses-space-asterisks-capital A-asterisks-close parentheses-frontslash convey?"
"Oh, you don't have the faintest idea, either, huh? Here's a tip, Risette, words were made to be used. If you insist on letting me know exactly how you feel when you write me one of your indecipherable little messages, then just tell me. Don't leave me some of the Universal Airhead Code because -- newsflash! -- I'm not familiar with it!"
"Senpai," a cool, clear voice cut through the sound of Souji's snapping and Rise's large, wet sniffles, "While I agree with your sentiment that verbal ineptitude is prevalent within this group, I believe this has gone on long enough."
"Has it?" Souji asked, voice oddly thoughtful.
"Yes. Quite long enough."
Souji paused for a moment, then flipped through his phone a moment before taking a very large, very deep breath. For a moment, it looked as if their leaders reign of terror had been brought to an end.
Then, Souji started screaming.
"NEW INFO W-BACKSLASH CASE. PLZ REPORT 2 MY HOUSE 2MORROW."
The group covered their ears in unison while Naoto's lip quivered dangerously and Souji continued to read off message after message at the same ear-splitting volume.
"Here's something that's gone on quite long enough," Souji panted, voice hoarse from shouting, "Your absurd non-sentences! It's not a telegram, Naoto! I'm not going to charge you an extra haypenny if you add a word or two to make some sense! And stop leaning on the goddamn caps-lo--"
There was a loud thwack, followed by the sound of a body hitting the floor. Naoto holstered her gun and took a breath before stepping over Souji's unconscious form and walking out of the food without a word.
"She really left a lump, huh?" Chie mumbled while Yosuke kicked Souji rather roughly onto his back.
"Should've used the trigger," Yukiko murmured darkly, eyes narrowed to slits. Kanji edged away from her meekly.
"Let's just go," Rise grumbled shrilly, flipping her long hair over her shoulder defiantly. Teddie shifted uncomfortably behind them, eyes darting down to their knocked out leader nervously.
"W-what about Sensei?"
Yosuke kicked him again, fists clenched before bending over to pick up his phone. He started deleting texts with alarming speed, making sure to keep the screen away from prying eyes. "He'll be fine," the brunette spat, tossing the phone back down once all evidence of himself had been eradicated, "C'mon."
Kanji lingered behind for a moment, staring at Souji thoughtfully before catching up to the others with long strides. Cracking his knuckles, the tall boy mumbled to himself more than anyone else.
"Thought we were supposed to be speaking Japanese…"
Apologies for any (also incredibly ironic) grammatical errors. :/