Work Text:
Kei Tsukishima had always preferred the language of certainty, the quiet elegance of logic laid bare.
There was a serenity in numbers, in the crisp predictability of an equation solved neatly, in the soft confidence of a formula that never failed.
Charts did not flush with embarrassment under someone’s gaze. Graphs did not falter when the air grew thick with meaning. Variables behaved, most of the time, if you understood them well enough. And when they didn’t, at least they had the decency to be transparent in their resistance.
Numbers, for all their cold reputation, could be comforting in a way people never managed to be.
The heart, however, was an entirely different kind of problem.
And Kageyama Tobio was the kind of problem that shattered every known formula, the kind that crashed into Kei’s life with all the chaos of a thunderstorm disguised in a volleyball jacket—bringing with him smudged ink on the edges of his hands, half-completed assignments that still scored higher than most, and a pair of eyes so startlingly blue Kei had to stop himself from checking if they were real.
He transferred into Kei’s advanced statistics class halfway through the semester—something about “consistently scoring too high on the regular tests,” of course—and, as if guided by some cruel twist of fate or a cosmic joke, was seated beside him.
“It’s just a seat,” Kei told himself the first day, repeating the words like a mantra.
But it wasn’t. It never was.
It was proximity, dangerous and charged. It was a thousand unspoken things hidden beneath the mundane act of sitting side by side. It was the edge of something he couldn’t name, humming low beneath his skin whenever Kageyama turned his head or muttered a question in that soft, serious voice that seemed designed to haunt the marrow of his bones.
Kei, being the strategist at heart he was, did the only thing he could think of: he documented. Notebooks became spreadsheets. Idle thoughts were converted into data points. His laptop hummed late into the night, not with schoolwork but with a shameful, secret rhythm—a catalogue of glances, brushes of hands, words that lingered longer than they should have.
File Name: Probability of Kageyama Liking Me Back.docx
There were rows upon rows. Every incident meticulously labeled. Every perceived smile dissected. Every touch, however accidental, assigned a probability score. It was absurd. It was obsessive. It was the only way he knew how to survive it.
Entry #14: “Kageyama shared his sandwich. Again.”
Interpretation: Possibly nutritional altruism.
Likelihood: 3/10. (Note: Peanut butter and jelly is not a love language.)
And yet—every time Kageyama acted without thinking, every careless kindness, every bright, oblivious grin—it hurt. Because Kei knew, deep down, that Kageyama never meant any of it. He just moved through the world the way he played: instinctive, brilliant, terrifyingly beautiful. He passed the ball without needing to look. He spoke without understanding the consequences. And Kei was left behind, calculating everything that couldn’t be quantified.
“You going to confess,” Yamaguchi said one afternoon, not even looking up from his own laptop, “or just build a statistical model of heartbreak in the form of a pie chart?”
Kei glanced up, offended. “I would never make a pie chart.”
“Line graph, then.”
“I’m not confessing.”
Yamaguchi raised an eyebrow. “You color-coded the spreadsheet.”
“That’s called organization.”
“You assigned numerical values to different smile types.”
“That’s called scientific rigor.”
“You have a column labeled ‘Moments That Emotionally Destroyed Me.’”
Kei shut the laptop with the finality of a slammed door. “I’m going to drop out. Move to Iceland. Change my name to something untraceable.”
But the universe had other plans.
A week later, their teacher announced the next assignment: a group project exploring real-world applications of statistics. And before Kei could even process the implications, Kageyama had already turned to him, eyes lit with unmistakable expectation.
“We’re partners, right?”
What was the probability of surviving eye contact like that? Kei didn’t even try to calculate it. He simply nodded, his heart thundering in his chest like it had just been given permission to fall.
Kageyama showed up to his house the next day with a backpack, three mechanical pencils, and not a single regard for personal boundaries. He kicked off his shoes with practiced ease, flopped onto Kei’s bedroom floor like it was something he’d done a hundred times, and stared up at the ceiling with a thoughtful expression.
“So,” he said, chin in hand, “what if we made our project about love?”
Kei blinked. “What?”
“People like love. They’ll pay attention.”
“I don’t like it.”
“That’s what makes it funny.”
And maybe it was funny, in a cruel and cosmic sort of way, but Kei could hardly think with the golden haze of late afternoon painting Kageyama’s face in soft light, turning all his sharp edges gentle, warm, unbearably close.
“Fine,” he muttered. “We’ll do love.”
He hated himself immediately.
The project spiraled into chaos within minutes. Kageyama couldn’t format a document to save his life, kept picking fonts that looked like they belonged in a haunted carnival, and proposed ridiculous hypotheses like, “Do people who like dark chocolate fall in love faster?”
“What does that even mean?” Kei groaned.
Kageyama shrugged. “You tell me. You’re the numbers guy.”
Kei leaned back against the wall, exasperated, and for a moment—just a moment—Kageyama looked at him in a way that made it hard to breathe. Not with frustration. Not with amusement. But with something soft, something curious, something almost reverent.
“You do this thing,” he said quietly, “where you act like you’re mean. But you’re not.”
Kei’s voice was sharper than he intended. “I am.”
“Not to me.”
“That’s because you’re an idiot.”
Kageyama smiled, if just slighty. “I like when you insult me. It’s better than when you pretend I’m not there.”
Kei’s lungs forgot their function.
“You’ve been weird lately,” Kageyama continued, gentler now. “You avoid eye contact, but then you stare when you think I’m not paying attention. You sit next to me, but you act like I’m a nuisance. I’m not great at feelings and stuff, but... it feels like something.”
And Kei, trembling beneath the weight of everything he’d never said, asked, “What are the odds?”
Kageyama tilted his head. “What?”
“The odds that you’d ever feel the same.”
There was a pause. Then:
“High,” Kageyama said.
And that word—so simple, so sure—hit Kei harder than any number ever had.
“I don’t know when it started,” Kageyama said. “Maybe when you corrected the teacher and looked so smug about it. Or when you rolled your eyes at me, and it somehow made the day brighter. I just... I always want to sit next to you. And when you don’t talk to me, everything feels a little off.”
Kei stared. Then laughed—a breathless, disbelieving sound. “I made a spreadsheet about you.”
Kageyama blinked. “You what?”
“Labeled every time you looked at me.”
“…That’s kind of weird.”
“I know.”
“I like it.”
“Of course you do. You’re an idiot.”
“And I like you too.”
The slideshow they turned in was barely finished, filled with grammatical crimes and private jokes, with one slide boldly titled: Love is Dumb But Statistically Worth It.
Their teacher gave them an A+, accompanied by a handwritten note that read, What the hell, but also—good job.
Kageyama sat beside Kei in class the next day like he always had—but this time, his knee brushed Kei’s under the desk and didn’t move. And for the first time, Kei didn’t move either.
That night, he opened his laptop one last time. He scrolled to the bottom of the spreadsheet.
Final Entry:
“Told me he likes me. Smiled like it was easy.”
Interpretation: I am completely, irreversibly doomed.
Likelihood: 100%
He renamed the file:
Probability of Love: 100%
And then, at long last, he let the numbers go.
He stopped calculating.
Stopped bracing.
Stopped pretending he didn’t already know the answer.
And he let himself feel.