Work Text:
Megumi Fushiguro does not understand love.
It’s a vaguely embarrassing admission, even to make to himself, so it’s not one he likes to think much about. Then again, in some cases, it’s entirely unavoidable, like when he accidentally brings it up to Gojo and is forced to sit through an hour-long lecture about Gojo’s own frankly depressing love life, or like right now, as he sits in the third row of fifth period calculus staring at the back of Yuuji Itadori’s head. Or, in other words, when he’s staring directly at the primary source for all his problems.
Although he feels bad calling Itadori a problem, even in the confines of his own mind. There’s nothing wrong with Itadori—frankly, he’s rather perfect in Megumi’s mind. Unfortunately, that’s where the very problem stems from, because as much as Megumi tries to convince himself that Itadori is just another high schooler, just a normal person with whom Megumi should be able to have a normal conversation with, he only ends up sticking his foot in his mouth any of the few times he has an opportunity to talk to the other boy with a blinding grin. And it’s not as if Megumi gets many such opportunities to begin with—Itadori and Megumi run in very different social circles, so the only time they really see each other is in the calculus class Megumi sits in now, and yet Megumi spends most of said calculus class staring at the back of Itadori’s head, sometimes even craning his neck to the side to see if he can sneak a peek at the doodles Itadori so often loves scribbling in class.
Because it doesn’t make sense. There’s nothing particularly special about Itadori, although he was rather handsome and he did have a brilliant grin and he was one of the kindest boys in the school and he was one of the best at baseball and he did love pets and—
—Megumi was getting carried away.
The point was, nothing about Itadori should be so abnormal so as to cause Megumi’s heartbeat to start pounding in his ears when Itadori flashes him a friendly grin or for blood to flush Megumi’s face whenever Itadori so much as looks at him, or, god forbid, for Megumi to forget every word in the Japanese language whenever Itadori asks him a question—
—and yet it does, and Megumi has no idea why.
“I just don’t get it,” Megumi mutters to himself, letting his pencil absentmindedly trace random spirals in the margins of his notebook.
“Don’t get what?”
Megumi almost falls out of his seat. He glances up to find Itadori turned backward in his seat to face Megumi with curious eyes, and Megumi almost chokes on his next inhale.
“Um,” he starts intelligently. “Hm. This problem, I…” He trails off, gesturing vaguely to what their teacher was drawing out on the chalkboard. “I just can’t seem to get this problem.”
Nice save, Megumi thinks, mentally patting himself on the back.
“Oh!” Itadori says brightly, and Megumi almost wishes he had sunglasses to protect against the force of Itadori’s blinding grin. “I can help!” He takes out a pencil from behind his ear and starts doodling on the upper margin of Megumi’s notebook. Megumi can only watch, fascinated. “See, because the parabola curves upwards, the limit approaches infinity. Infinity over infinity is one, so the limit is one!”
Totally wrong, Megumi thinks. His lips twitch into a small smile anyway.
“Thanks, Itadori.” He hesitates. “You’re really smart.”
Itadori’s grin turns sheepish. “Happy to help!”
Itadori turns back to his own desk, and Megumi is left staring at a wobbly parabola and an entirely incorrect equation below it. He lifts his eraser so as to fix the math, but after a beat of hesitation, he sets the eraser back down.
There was no harm in that, right?
“You gotta be fucking stupid to think that’ll work.”
Megumi lifts his head from his arms enough to return the unimpressed glare Kugisaki currently shoots at him. Kugisaki meets his stare evenly, until Megumi’s forced to break it and look away.
“It’s fine. It’s harmless.”
Kugisaki scoffs. “I’d like to hear you saying that once you start failing calculus.”
“It won’t get that bad,” Megumi says with a frown. “Anyway, it works, doesn’t it? Every time I tap him on the shoulder and ask him about a concept, he teaches it to me.” He pauses. “He… tries to teach it to me,” he amends, and Kugisaki rolls her eyes.
“You’re kind of pathetic, you know?” Kugisaki takes a loud sip from her milk carton. “Dumbing yourself down just so you can hear this guy talk about math he doesn’t even know. Worst idea of flirting I’ve ever seen.”
“Well, your idea of flirting is just challenging Maki-san to an arm wrestling competition every week,” Megumi points out, and he ignores Kugisaki’s subsequent spluttering to continue. “Anyway, it’s not flirting. It’s just… I don’t know.” He looks down, a small smile forming on his face. “I like talking to him. Even if it is about math he doesn’t actually know.”
Kugisaki sticks her tongue out in a fake gag. “That is disgusting. You are disgusting.”
“I’m going to tell Maki-san you’re homophobic.”
“Megumi fucking Fushiguro, you will NOT—”
And so it becomes something of a routine. Megumi will zone out for half of the class, tap Itadori on the shoulder when he gets bored, and ask please, oh please, wouldn’t Itadori explain this concept to Megumi? Itadori is always much too happy to oblige, and Megumi has no problem listening and nodding to everything Itadori eagerly talks about, even if half of it ends up being the exact opposite of the right answer.
Either way, it’s a routine that works. At least until—
“Itadori, could you explain this question?”
Itadori turns around with his usual grin. “Sure!” He taps Megumi’s notebook. “See, you’ve already got the right work, here, but you have to simplify so that…” He leans over to cross out some of Megumi’s writing, before leaning back with a satisfied beam. “Get it?”
Totally wrong, Megumi thinks.
He smiles weakly in response anyway. “Thanks. I can never seem to understand these type of…”
“Keep up the good work,” their teacher interrupts, dropping a test paper on Megumi’s desk with a rather incriminating 98 scrawled on the top.
Itadori eyes the test paper curiously. Megumi feels the visceral urge to crawl into a hole and die.
“Seems like you can understand it pretty well!” Itadori notes with a lopsided grin. Megumi coughs weakly.
“Yeah, I just…” He trails off. He has no idea how to finish the sentence.
After another quick glance at the test paper, Itadori turns back to his own seat. Megumi glares a hole at the mocking, taunting 98 and mentally apologizes to himself and Kugisaki for what he needs to do next.
“Mhm, so this series converges, but because of the limit, it actually diverges—”
Totally wrong, Megumi thinks.
“Right,” he says instead. “That makes sense.”
“Not your best work, Fushiguro-kun.”
Megumi glances up at his teacher’s voice, even as she moves past him to drop another test on the student’s desk behind him. His gaze falls to the test paper on his desk, and his breath hitches at the 64 that stares up at him.
Itadori whistles under his breath when he catches sight of the score. “Yikes,” he murmurs, casting a glance at his own 72 laying on top of the mess of papers on his own desk before his eyes dart back to Megumi’s.
“Wow,” Megumi says carefully. “I guess at this rate I might need tutoring.”
Itadori’s head cocks to the side. He scratches his cheek with his finger.
“You know, if you want, I could—”
“Yes,” Megumi interrupts.
Itadori blinks. “What?”
“I mean,” Megumi starts again, even as he feels his face start to heat up, “yes. Um. You could tutor me?” At Itadori’s silence, Megumi swallows. “If you—if you wanted. That is.”
Itadori pauses in consideration. “Sure,” he agrees with a shrug. “Your place or mine?”
All of Megumi’s breath leaves him in one great exhale that he hopes isn’t as noticeable to Itadori as Megumi thinks it is.
“Whichever you want.”
They end up alternating. One week it’s at Megumi’s, and the next it’s at Itadori’s, although Megumi is very careful to arrange it so that they never run into Gojo—Megumi isn’t sure if he would be able to take Gojo’s no doubt endless wheedling if he ever knew Itadori.
And it works. It works, primarily because half of the time the two of them are never really doing calculus at all, but instead talking about their favorite books and their favorite movies and that one time Itadori hit a baseball so hard that it physically disappeared—
“—and we looked everywhere for the baseball, even the coaches were outside the field, but no one could find it at all, it’s like it totally disappeared out of the stratosphere or something!”
Megumi hides an amused grin behind his hand. “So what about the rest of the game?”
Itadori leans in with wide eyes. “We couldn’t play without a ball, right?” he begins. “My friend, Todo, he’s the captain—he decides all we need is another round-ish object that we can use to continue playing. He reaches under his hat, and…” He pauses for dramatic effect and lets the expectant silence settle. “He pulls out an egg.” He leans back with a satisfied smile. “I guess you can imagine how the rest of that game went.”
A snort slips out of Megumi. “An egg,” he repeats incredulously between snickers muffled behind his hand. “Why did he have that just under his hat the whole time, and why would he think he could play baseball with it?”
Itadori’s grin widens. “We tried to tell him it wouldn’t work, but he wouldn’t listen,” he says with a shrug. “Anyway, he was the only one willing to hit it, so…” He trails off, and Megumi’s shoulders shake with unsuccessfully suppressed laughter.
“I wouldn’t want to be him,” Megumi admits, grinning at his hands, but when Itadori’s expected response doesn’t arrive, he glances up to find Itadori staring at him curiously. “What?” Megumi asks defensively. “Is there something on my face?”
“No,” Itadori responds slowly. “I just realized you have a really nice smile.”
Megumi’s pretty sure he’s a heartbeat away from exploding into flames.
“Ah,” he says intelligently. He should probably say something else, right? Was “thank you” an acceptable response? No, that was too embarrassing, right? What else was he supposed to say? Was saying that Itadori’s smile could rival the sun in its brightness too much in response? Would saying “you too” really encompass what Megumi meant? Did it matter at all?
Megumi’s train of thought entirely halts when he realizes Itadori’s eyes are on his lips.
Oh, Megumi thinks when he realizes he’s now close enough to Itadori to count the light smattering of freckles on his cheeks, although he doesn’t remember moving closer himself, and he doesn’t remember watching Itadori move closer either, but here they are anyway, inches apart, and something in Megumi flickers and burns against his chest, this is love.
Or maybe it’s not, because Itadori sharply pulls away just before their faces meet.
“Wait,” Itadori says, and there’s a flush high on his cheeks that Megumi is so captivated by that he almost misses Itadori’s next words, “I don’t think we should do this.”
Megumi blinks. “What?”
“I, um.” Itadori looks away, scratching behind his ear. “I really like you, you know.”
Megumi blinks again. “What?” he repeats.
“I really like you,” Itadori says again, “but I don’t think we should do this.” At Megumi’s blank stare, he quickly hurries to continue. “You know, I just—I don’t want to take advantage of you.” He looks away. “Since I’m your tutor and all?”
Megumi’s face burns hot with something like embarrassment. He leans further away.
“I’m sorry, I just—”
“You’re not really even my tutor, though,” Megumi interrupts. Stop fucking talking, something in Megumi screams, but the blood rushing in his ears is a little too loud and it’s a little too easy to ignore the warning. “I mean, I was faking being bad at math to get you to talk to me.”
Itadori looks at him strangely. “What?”
Megumi needs to stop talking.
“I mean, I’m not actually bad at calculus.”
Megumi does not stop talking.
“Actually, you’re kind of bad at calculus, but—”
“Wait,” Itadori interrupts, and Megumi’s mouth blessedly snaps shut. “You’ve been… faking? You’ve been lying this whole time?”
And of course now is the moment Megumi’s mouth decides to remain shut.
Itadori blinks slowly, his eyebrows furrowing. “Just for an excuse to talk to me?” he continues. “Why wouldn’t you just… talk to me?”
Because I’m really fucking bad at this, Megumi mourns internally. He still can’t seem to force his mouth to move, although even if he could, he’s not exactly sure what he could say to salvage the ruins. He pulls his eyes away from Itadori’s searching gaze to stare at the notebook he hasn’t written in for the past two hours.
Out of the corner of his eyes, he sees something in Itadori’s eyes dim.
“I guess I got it all wrong, then,” he murmurs. “I should go.” He haphazardly shoves his items into a backpack that he slings over a shoulder. He casts one last look at Megumi behind his shoulder before heading out the door, leaving the echoing absence of an energetic farewell lingering in Megumi’s ears.
“Wait,” Megumi says stupidly to an audience of none after too many minutes have passed, “but this is your house.”
As expected, he doesn’t get any response in return from the walls around him.
“I messed up.”
Kugisaki takes a loud and annoying sip from her milk carton. Megumi’s not sure where she keeps getting them from.
“Yeah, what happened to ‘it’s harmless,’ huh?” she asks with a pointed eyebrow raise. Megumi slumps lower in his own seat.
“I should fix it,” he mumbles to himself. “I want to fix it. I need to fix it.”
Kugisaki takes another loud sip. “I’m not sure if verbal manifestations have the best track record of success, buddy.”
“Maki-san believes in them,” Megumi lies easily, and Kugisaki’s eyes widen before she quickly looks away.
“I mean,” she coughs out. “I never said they were always ineffective, I just…” She trails off before crossing her arms with a pout. “Whatever. You, Itadori. What’s the plan?”
“The plan,” Megumi mutters. “Do you think I should ask him about last night’s calculus homework?”
“You actually suck at this.”
Megumi does not end up asking Itadori about last night’s calculus homework: instead, he spends the first few minutes right before class pacing around and stealing glances at Itadori’s empty desk, before snatching a piece of paper from his own desk, scribbling something down, and placing it face down on Itadori’s desk before he can think twice about it. He slides into his own seat just in time for Itadori to enter.
Itadori doesn’t meet his eyes. Megumi shouldn’t be surprised, but it still stings, just a little.
Itadori sits down. Megumi watches him flip over the piece of paper on his desk. He holds his breath.
“Is this yours?”
Megumi’s shoulders tense. “Um,” he says, unprepared for Itadori to so quickly ask him about the note. “Yeah, it’s, uh. I wrote it. For you.”
Itadori’s eyes quickly flit over the contents of the paper again—out of curiosity, Megumi notes, and not malice. Megumi’s shoulders relax just a bit.
“What’s it mean?”
Megumi blinks. “What does it…?” he starts to repeat, feeling his ears begin to heat up even at the memory of what he had hastily written on the paper.
My love for you is a monotonically increasing unbounded function.
“It’s…” Megumi starts again. “A pickup line. It’s a pickup line,” he mumbles, half to himself. At Itadori’s confused blink, he feels the need to explain. “A monotonically increasing unbounded function. It, uh, has no upper bound, and it’s always increasing.” He quickly sketches it out on his notebook and desperately tries to ignore the burning of his ears. “So its limit as it approaches positive infinity doesn’t exist…” He trails off. He sets his pencil down.
“Oh,” Itadori says, staring with wide eyes at the note again. “Oh,” he repeats, and a shy sort of grin unfurls across his face and Megumi is captivated.
But Megumi snaps himself out of it. “I’m sorry,” he murmurs earnestly. “I didn’t mean to lie to you for so long. You were just so… you. And I didn’t know how to even approach you, let alone hold a conversation with you.” He takes a breath. “I do now. I think.” He winces. “If you’ll have me, that is?”
Itadori hums in contemplation, even as he continues staring at the note with a dopey grin. “No more lying?” Itadori asks when he finally lifts his eyes up to meet Megumi’s.
“No more lying,” Megumi promises.
Itadori’s grin softens.
“I wouldn’t mind being your monotonous unbounded function, then!” he says brightly, and Megumi bites the inside of his cheek to suppress his own grin that threatens to unfurl.
“That’s not—” Megumi cuts himself off with a satisfied sigh and small smile. “Never mind.”
“Say, Megumi, since you’re so smart, do you think you could tutor me?”
“...you know, my friend Kugisaki has this study group with my cousin that I’m sure she’d love for you to join instead.”