Work Text:
Shidou has fucked up
He has made the rookie mistake of procrastinating when choosing a class for the next semester. Now he is crouched in front of his laptop a day before the deadline scrolling past all the classes that are so filled that he can't even get on the waitlist.
Fuck
It will be his final semester at his uni as an art major, and his GPA is hanging on for dear life. He has put off this one mandatory Pre-Calc class for way too long and now he’s bearing the brunt of it. No, seriously who the fuck decided an art major has to pass math to get a degree? And it's not even a geometry class but Pre-Calc? Really? Fuck this fuckass university he couldn't wait to get out of here.
He’s on the last page of the course catalog, heart-dropping at the thought of paying for one extra semester until he sees a singular class that is still to be filled. ‘MATH 150’, written in bold letters with 15 seats unfilled, and the class begins at 1 pm and ends at 2:45 pm. Woah ? did he just win the fucking lottery? nah this feels more rewarding. Not only did he manage to get in a class but it also had the perfect class timings that fit his schedule.
Still, 15 empty seats in a high-demand class feels about as suspicious as a "free iPad" email. Sensing danger, he turns to the most trusted academic resource known to college students—RateMyProfessor.com , where professors are judged on a scale from ‘would take again’ to ‘legally shouldn't be teaching’. With the precision of a detective (or just a procrastinating student avoiding actual work), he types in the professor’s name and the course number, bracing himself for whatever horror stories or unexpected praise—awaits.
Right … ofcourse
He then scrolls further down to read the reviews
Shidou slams his laptop shut and lays down on his bed.
he sighs.
So… basically he’s fucked once again.
But hey! At least there’s a silver lining to this whole thing– apparently the professor is super hot.
—
The reviews weren't lying, standing in front of the entire class as she took out the materials from her handbag, anyone with eyes could tell that Rin Itoshi was attractive. But that is not the issue at hand for Shidou, it is that he thinks he might’ve severely underestimated how fucking attractive she was going to be.
Ms. Itoshi was the living embodiment of every teenage wet dream he’d ever had. Her long, dark hair framed her face perfectly as she rummaged through her bag, and from where he sat, he could make out the sweep of her impossibly long lashes and the glossy curve of her lips, set in a slight pout as she focused on her task. She wore a crisp white button-up tucked seamlessly into a fitted pencil skirt that reached just past her knees—strictly professional, yet sinful in the way it clung to her body.
And her tits. Jesus fucking Christ , her tits.
Shidou shifted uncomfortably in his seat, hands reaching down to calm Shidou Jr who was very enthusiastic about whatever he was witnessing in front of him. After arranging her things in an orderly manner on the lectern, she straightens her shirt and pulls down her skirt, shidou follows her every movement as though he’s in a damn trance.
She scans the room with a stern expression, her eyes land on him for a brief moment and he couldn't help but give her a smitten grin, she quickly averts her eyes and focuses straight ahead.
“The syllabus is not a suggestion—it is law. If you haven’t read it yet, you are already behind.”
She paces,
“Pre-calculus is not ‘hard.’ Pre-calc is logical. If you find this material difficult, it is because you have not trained your mind to think critically. That is your problem, not mine.”
The class breaks into a strew of hushed murmurs and worried faces. Shidou’s grin widens.
This bitch is fucking crazy
He likes crazy
Unfortunately for him, he can't afford to sacrifice his grade for it
“I expect silence unless you are answering a question. Mathematics requires discipline, and so does my classroom.”
The class hushes
“Some of you will fail. That is reality. If you do not study, if you do not practice, you will fail. If you expect an easy A, transfer to another section. Do not come asking for extra credit, there is no extra credit in life, and there is none in my class.”
She pauses her strut, voice softening a little
“However… if you work, if you put in the effort, you will survive. Maybe even thrive. Mathematics rewards those who respect it.”
Oh? Maybe ice queen here has a soft side to her after all...
Shidou raises his hand
All eyes fall on him including the teal gaze set before him
“What is it?” Rin asks looking him up and down
“Professor, when are your office hours… you know, if I ever needed a more private discussion?”
He carefully enunciates each word, layering his tone with a subtle yet unmistakable double meaning. Shidou could hear a few gasps and * ohs * from the back but his gaze was fixed on Rin who seemed taken aback by his question. He feels victorious in catching her off guard.
She looked at him wide-eyed before a frown replaces it.
Clearing her throat and gaining her composure she answers,
“My office hours are clearly listed on the syllabus you would know this if you had actually bothered to read it. And they are strictly for academic purposes, nothing else. Now, if you’re done wasting my time with… whatever that was, do you have an actual question, or should I move on?"
"That's all from me ma’am” he shrugs, raising both hands and displaying his signature smirk.
She eyes him one last time, her gaze lingering just a second too long, as if debating whether to say something. Instead, she straightens her posture, and turns on her heel, striding toward the board with forced composure. The faintest tension clings to the air, crackling like static.
She quickly scribbles some sort of complex equation, “If you cannot solve this by next class, drop the course. I do not do hand-holding nor do I wanna hear excuses. "I didn’t understand" is not an excuse—it is a confession of your own laziness.”
Behind her, Shidou chuckles to himself, lips curling into a smug grin. He leans back slightly, basking in his own handiwork– this deliciously awkward atmosphere of dubious intent. He’s gotten under her skin and caught her attention, surely he can figure out a way to pass this class.
—
Walking into the class he noticed a lot more empty seats. Rin Itoshi’s speech yesterday had definitely driven away a good portion of the students. He sat in the front row for .. uh reasons– plopping his chunky backpack with art supplies onto the chair beside him before pulling out his workbook and stationery. It wasn’t lost on him how the other students carefully avoided sitting next to him as if he carried the plague. Then again, Shidou knew he stood out like a sore thumb in a room full of normies, with his funky hair, piercings, and bold makeup. His antics yesterday might have played a role as well, but he couldn’t care less about what these insignificant fucks thought of him. The only thing that mattered was passing this damn class—and if he happened to catch the eye of a certain busty spinster with the temperament of a street cat, he sure as hell wasn’t about to block his blessings.
Rin Itoshi walked in right when the clock struck 1 pm, the energy in the room shifting into a more tense one as she made her way to the front. Shidou perked up from his seat eyes trailing her when he noticed a dude following behind her. He was slightly taller than her, with dark hair parted in the middle as if his mommy had styled it for him. He moved timidly with a stupid smile plastered on his face and made his way to the teacher's desk. Shidou’s mood sours a bit for some reason.
“Alright you all better have submitted the work I assigned yesterday, my classroom isn't meant for slackers”
She glances at him like it was a direct attack and Shidou makes a kissy face.
Seemingly offended she turns away from his section.
“Oh right and this is Nanase Nijiro, my TA, if you have any questions you can head to him if you want, instead of bothering me with anything nonsensical ” , she says pointing at the dude who looks alarmed now that all the attention is on him.
“Nanase do you have anything to say to them ?” Rin asks,
Nanase clears his throat, offering a friendly smile as he scratches the back of his head.
"Uh—hey, everyone! Like Ms Itoshi said, I’m Nanase Nijiro, your TA. Feel free to come to me if you need help with anything. I promise I don’t bite," he chuckles, glancing around the room. "I’ll do my best to answer your questions, and if I don’t know something, I’ll find out for you. So, uh… yeah! Don’t be shy!"
His relaxed tone and approachable demeanor seemed to ease the tension in the room, and a few students even let out relieved chuckles.
Well– everyone except Shidou, who, at that moment, decides he really doesn’t like this guy.
He spends the rest of the class trying to win some kind of one-sided dick-measuring competition with the poor unassuming TA. Leaning back in his chair, Shidou sprawls out, legs spread wide, arm draped over the seat next to him—a petty display of dominance. He knows exactly what he’s doing, but if there’s one thing about Shidou, it’s that he’s utterly shameless.
Nanase, clueless at first, only catches on much later. The moment he does, a wave of self-consciousness hits him. Shifting in his seat, he tries to focus on the lesson, but it’s hard to ignore Shidou’s unrelenting stare– like a predator sizing up a prey, daring him to engage.
Meanwhile, Rin, oblivious to the silent battle unfolding behind her, continues her lecture on functions and notations—or some shit like that.
Nanase pretends to type something on his laptop but he decides to glance at Shidou one more time only to regret it.
Shidou gestures to him in what clearly is a threat, meet me outside if you dare, Nanase deciphers loud and clear from his expression,
For whatever reason this big dude was trying to pick a fight with him, he didn't know, what he knew was that he had to get away soon, or else this was going to escalate.
He rises abruptly from his seat surprising Rin who halts her writing on the board to look at him questioningly,
“What happened Nanase?”
“Um I just remembered I had an urgent task to attend to-” He stammers, hastily shoving his things into his bag “I'm really sorry Ms Itoshi but um- I gotta go”
Rin quirks a brow. "Uh… sure?"
Nanase glances around the room before offering a quick, awkward bow. "Sorry, everyone, but I need to leave now." His eyes flicker to Shidou one last time—then he’s gone, bolting out the door like his tail is on fire.
Fucking pussy
Shidou chews on the end of the pencil, ogling at Rin, who looked confused by the whole ordeal. The class also seemed to be in a similar dilemma, hushed whispers and stifled laughter ensue.
"Alright, that’s enough," she says, voice calm but laced with authority.
The murmurs die down instantly, though a few hushed chuckles linger. She scans the room before her gaze lands on Shidou, sharp and unwavering. Her expression doesn’t change, but the pointed look she gives him speaks volumes— I know you had something to do with this.
Shidou, unfazed, simply smirks around the pencil still between his teeth.
—
In the first few weeks, Shidou managed to get his homework done by threatening a nerd he singled out after class. It wasn’t that he was incapable of solving equations or wrapping his head around mathematical concepts, despite what some might assume. In reality, he just had a deep-seated hatred for anything rigid, structured, or bound by unchangeable rules. Math, science, anything that demanded precision without room for spontaneity—it all felt suffocating to him, like being forced into a cage where there was only one right answer, and no space to twist things into something uniquely his own. That was exactly why he gravitated towards art. With a blank canvas, there were no rules, no restrictions, nothing forcing him into a mold. He could throw himself into it completely, let the chaos spill out onto it however he wanted, and somehow, people would still manage to pull meaning from his madness.
He had grown accustomed to the laid-back attitude of his art professors, the open-minded and progressive atmosphere of his peers, and the overall flexibility that came with his major. The rules were lenient, creativity was encouraged, and there was always room to interpret things in his own way. It was an environment where spontaneity thrived, and he had fully embraced that freedom. So, when he found himself in a high-intensity, logic-driven class like this one, he might have approached it a little too casually, assuming he could get by with the same laid-back attitude. It didn’t take long for him to realize that wouldn’t be the case.
Over the course of a few weeks, Shidou Ryusei had managed to get on his math professor’s last damn nerve.
It went like this,
Week two:
In the middle of a seemingly normal class, just as Professor Rin was explaining a particularly tedious problem, Shidou suddenly burst into loud, uncontrollable laughter. At first, his classmates exchanged confused glances, unsure whether he had actually lost his mind or if this was just another one of his usual antics. His laughter, however, only grew louder, drawing attention away from the lesson and completely derailing the flow of the class.
Professor Rin, visibly irritated, exhaled sharply before making her way to his desk, her heels clicking against the floor with unmistakable frustration. If Shidou found something so hilarious in the middle of a math lecture, she needed to see for herself. "Alright, antenna head," she sighed, arms crossed, "what the hell is so funny ?"
Still grinning like an absolute menace, he turned his calculator around to show her the screen, flipping it upside down with dramatic flair. 5318008.
‘Boobies’
Like a goddamn middle schooler.
For a long moment, there was silence. Rin just stared at the calculator, then at Shidou, then back at the calculator, as if her brain refused to process the sheer stupidity of what was happening. Meanwhile, Shidou was practically vibrating with barely restrained laughter.
Without a single word, she snatched the calculator out of his hands so fast that he barely had time to react. The laughter died in his throat as he watched her march back to the front of the classroom.
“Let’s see how you can solve problems without a calculator”, she said, holding it up for the entire class to see while glaring at Shidou.
wave of murmurs and muffled laughter rippled through the classroom. Shidou groaned dramatically, slumping onto his desk like she had just rained on his parade.
“Damn, Prof what a killjoy”
“Also it's Shidou Ryusei” he repeats with an exaggerated pout
Rin raises an eyebrow, “what?”
“My name. It's Shidou Ryusei, ma’am” ,sentence ending with his grin reaching up to the corner of his eyes.
Rin stares at him with a blank look before turning towards the board.
“Whatever”, she says pointedly
She held his calculator hostage for a full week.
Week three:
Rin catches him doodling in his workbook. A detailed eye drawing that has suspiciously long bottom lashes.
At this point, Rin has about had it with his ass.
She goes off on him in front of the whole class,
“You know, for someone who spends all day finger-painting their feelings, you sure have a lot of confidence in a subject that requires actual logic."
She scoffs, “I’m sure the world is dying for another starving artist who can’t do basic math."
This irks Shidou who spits back, “are you insulting me coz I’m an artist ?”
Rin scoffs, arms crossed as she looks down at him.
"Of course, you’d rather lose yourself in mindless scribbles than deal with something that requires actual logic. Any subject that doesn’t abide by facts and reason isn’t worth my time– but I guess when your whole world runs on self-indulgent scribbles, reality must be optional."
Shidou could hear the veins popping on his forehead.
She knows exactly what buttons to push to piss him off.
“See, that’s where you’re wrong, Professor. Art isn’t trapped by stiff rules or cold, lifeless logic- it’s what lets people escape the dull little boxes the world tries to shove them into. Math might explain how the universe works, but art? Art makes you feel it. It takes chaos and turns it into something worth experiencing. And honestly? I’d rather lose myself in ‘so-called nonsense’ than live in a world ruled by nothing but numbers and equations."
Rin’s frown deepens hearing his speech
They spend a good minute staring at each other like there is some kind of silent war of words being fought between them purely through the power of their angry stares. The rest of the class feels the pressure as well, like they're being privy to a passionate debate club match-up.
Ms. Itoshi positively looks pissed while Shidou tries his best to smile despite the visibly pulsating veins on his temple.
It was Rin who breaks away from their stare-off.
“Hmph” she mutters and walks to the front of the class.
“There will be a quiz tomorrow on chapters 1,2,3 … and 4”, she announces the last chapter while staring directly at Shidou, like she’s challenging him. A silent dare. See if you can pass it her smug expression seems to say.
The entire class bursts into groans and sighs. Some students shoot dirty looks at Shidou.
“Ugh, why do we have to suffer for his stupidity??”
“God I hate this class man”
He hears his frustrated classmates complain behind him.
They can keep yapping for all he cares. His attention is on one singular person in this whole entire room. She stands before him with a placid expression like she’s already ready to move on to the next lesson after dropping a bomb on the whole class.
already thinking ahead, already waiting for him to fail.
Shidou smirks. Challenge accepted.
—
So yeah, he failed that quiz.
He was foolish to think he could ace a four-chapter math quiz without practice. He didn't wanna prove the art student stereotype right but… dammit Rin Itoshi, she got him this time. The quiz wasn't too hard either he could recognize a few problems they did in class, but his negligence has cost him his overall grade to fall below 70%.
He checked his syllabus and found out they had 2 exams that accounted for 80% of the total grade. The first exam is coming up in three weeks. So if he doesn't get his shit together, he can say goodbye to his graduation plans.
He had to lock in.
Shidou tries . Really, he does. He shows up to study groups, makes an effort to meet up with classmates, and–for once–it’s not just for show. This time, he actually wants to study. He actually wants a good grade on the upcoming exam.
But his reputation precedes him.
The moment he joins a study session, it’s like someone sounded an alarm. Students suddenly remember they have “other plans,” hastily packing up their books. Someone’s phone miraculously rings with an “urgent call,” and another suddenly recalls a “prior commitment.” One by one, they scatter, muttering half-baked excuses that might have been convincing if Shidou wasn’t so painfully aware of what was happening.
Like hell, he doesn’t see right through them.
Man, this isn't going anywhere.
He isn't gonna bow down in front of that wimpy TA though, fuck that guy and his stupid hairstyle and his bug eyes.
There was only one option left.
—
Standing in front of her office, Shidou took a deep breath and steadied himself before stepping inside. The room was rather spacious and minimalistic, the air within was cool and still. Carrying the faintest scent of paper and polished wood.
Enclosed within two cubicle panels sits Rin Itoshi. Who at the moment seemed engrossed in some kind of paperwork, the faint scratch of a pen against paper was the only sound in the room. She was wearing one of those fancy sleek rimless glasses that sat delicately on her sharp features. Standing right where he is, she appeared like some kind of pristine marble statue– composed and sacrosanct, adorning a serene expression so different from the resting bitch face she normally walked around with. Shidou swears he could carve her out on a precious stone and it still wouldn’t quite capture the elegance she exuded now.
Shidou’s musings end when she finally notices him standing– alarmed as if she wasn't expecting anyone to show up during her office hours.
A beat passes between them before her expression shifts from startled to a mischievous smirk. With the slow, deliberate flair of a movie villain, she removes her glasses, taking in the full spectacle of his "academic catastrophe" in all its raw glory.
Damn
This is so humiliating
“Heh, A rousing speech about escaping dull little boxes, only to end up trapped in a very small, unforgiving box labeled 'F' Mr. Artist?”
Ouch
touché
"If you're here to argue about your grade, save yourself the trouble and head right back out. Your scores are final. This isn't a charity, and I'm certainly no philanthropist.", she says looking at his sheepish face.
“Um I’m here to ask you to teach some concepts I don't get”, he says in a low voice
Her frown deepens. Shidou mentally prepares himself for a good lashing.
“Hah! You screw around during class hours, bother other students with your stupidity and argue with me like some kind of know-it-all, you are reaping exactly what you have sowed”, Rin accuses him in an exasperated tone.
“Uh, I'm sorry …I was wrong?”, Shidou makes a shameless attempt at an apology, shoving both hands into his pockets.
Rin goes back to doing her paperwork, “Get out antenna head, I don't have time for this”
This won't do.
Shidou decides to lay it all bare. Screw it—this was his battle to fight, his future on the line.
“Please Prof you are the only person who can help me pass this class, If I don’t, I won’t graduate. I’ve tried study groups, but nothing clicks. And the TA is always swamped with students who are too afraid to come to you (half a lie because he wouldn't be caught dead asking Nanase’s help) and honestly…I’d rather ask you. Weren’t you the one who said that mathematics rewards those who respect it? That if you put in the effort, it will pay off? Well, I’m here to test that. I know I’ve been a pain, I know I’ve screwed around—but I’m asking for one more chance. Just tell me what I need to do, and I’ll do it."
He spoke with all the sincerity he could muster up.
Rin studies his face, searching for any hint of irony.
Finding none, she sighs and leans back in her chair, the movement pulling her shirt taut–buttons straining to keep her goods in place. For a moment, Shidou completely loses his train of thought.
“Tch, Fine. This isn’t a favor, and it certainly isn’t because I enjoy your company... Let’s get a few things straight. One, you show up on time. If you’re even a minute late, don’t bother knocking. Two, you actually put in the effort. I am not here to spoon-feed you answers. And three… if you start with your usual nonsense, this arrangement is over. Understood?", She fixes him with a sharp glare, voice firm and unyielding.
Shidou nods his head and does a hand salute “Yes ma’am! I won't disappoint you”
“Yeah yeah, now scram”
“Wait I thought we were-”
Rin shoots him a glare that shuts him up before turning her attention back to her paperwork, pointedly ignoring his existence.
“Right so I’ll come by tomorrow”, Shidou says awkwardly as he turns around to leave.
She doesn't say anything. Rin Itoshi and the stick up her pretty ass.
“Hey Prof”
“You're pushing it”
"Just soaking in your presence, Prof. Gotta get used to it before our big day tomorrow." Shidou turns back, and shoots her a wink–then blows her a kiss with the most shit-eating grin ever.
"Get. Out." Rin bares her teeth
"You’ll miss me when I’m gone."
He only leaves when she reaches for something to throw at him.
—
Shidou is now fully convinced that his professor is some sort of math demon, cruelly disguised as a beautiful woman to lure unsuspecting fools into a world of suffering.
He also comes to another, far more humiliating realization–his math fundamentals might not be as solid as he once confidently believed. That much becomes painfully obvious as his ear is being ruthlessly twisted by one very angry Rin Itoshi.
"Are you seriously telling me you forgot how to factor a quadratic equation?!" she snaps, voice sharp enough to slice through steel and his last shred of dignity.
Shidou winces, flailing slightly. “Ow, ow, okay, chill! I was just testing you, Prof—”
She twists harder.
"Try again."
Shidou sulks retrying the problem for the third time.
When he signed up for private lessons from Ms Itoshi he wasn't really expecting corporal punishment. although he can't say he’s surprised– she does have a violent streak.
She’s lucky she’s hot.
He steals quick glances at the glimpse of cleavage revealed by her undone buttons. He’s noticed she leaves them undone whenever she’s in her office, unwinding. Not that he’s keeping track or anything…
Suddenly, he’s feeling very inspired today.
“Did I do it right this time Prof?”, he asks turning the book towards her
“Hmph! Don't get cocky now, even a grade schooler could solve this and it took you three tries”
—
Within a week, Shidou had made noticeable progress in the subject and was getting the hang of Rin’s teaching style. She was brutally direct and super detail-oriented when explaining things, never sugarcoating anything or letting him slack off. Every concept was precisely broken down, and she expected him to grasp it fully—no shortcuts, no half-baked answers.
Surprisingly, he didn’t mind it. In fact, he actually started to like her no-nonsense approach. There was something refreshing about how she cut through the fluff and got straight to the point. Instead of feeling pressured by her high expectations, he found himself stepping up to meet them, realizing that her tough methods were exactly what he needed to improve.
He even got 17 out of 20 on a recent quiz, excited, he held up his result in front of Rin, expecting some kind of reaction. But all she had to say was,
“Hmph, still lukewarm”
She’s such a tsundere.
Rin snatched the quiz sheet from his hand without a second glance at his score, her eyes immediately scanning for mistakes. Within seconds, she let out an annoyed sigh, and tapped her finger against one of his wrong answers.
"Seriously blockhead? You messed this up? This step is completely off—you weren’t even close. And here–did you even bother reading the question properly? This is just sloppy. You should've at least gotten a 19 if you actually paid attention."
She continued going through each mistake with sharp, pointed criticism, as if his solid score meant nothing compared to the mistakes she expected him not to make.
He sighed, pulled his chair closer to her, and sat down.
She continues ranting, calling him unbelievably stupid for making such careless mistakes, her sharp tone relentless. At some point, he just tunes her out, nodding occasionally to make it seem like he's listening.
Rin Itoshi, what a fascinating character. She carries herself like she’s above caring, acting cold and detached, but the truth is painfully obvious. She cares a lot . She effectively masks it with her strict, unrelenting attitude and harsh words, but underneath it all, she’s deeply invested in the success of her students—even if she’d rather drop dead than admit it.
Or, maybe…just maybe, it’s special treatment?
Shidou chuckles to himself, interrupting Rin’s lashing.
“Do you find this funny?”, She asks
He sits up straight feigning seriousness, “No ma’am!”
“Redo these ten times”
By now, he’s more than used to her over-the-top demands. Without complaint, he picks up his pen and gets to work, flashing a lazy grin. "Aye aye, Prof!"
“Stop calling me that you roach head”
Shidou raises a hand in a mock salute, his eyes still fixed on his work as he smirks, "You know, Professor, for someone so cold, you sure have a way of making people want your approval."
Rin scoffs, flipping the page with a little more force than necessary, "Don’t be ridiculous."
Curious, Shidou sneaks a glance at her face. The slight tension in her posture and the faint pink dusting her cheeks say far more than her words ever could.
How cute.
—
Um… so Shidou has a crush on his math professor.
It was a fleeting realization, he almost felt silly for taking so long to figure it out.
Rin is seated beside him, explaining a problem with her usual sharp precision, her voice even and focused. He should be paying attention to the equation in front of him, but instead, his eyes keep drifting–to the way she moves, the way she speaks, completely absorbed in what she’s doing.
Shidou has always admired people who are passionate, no matter the subject. There’s something contagious about it, the way enthusiasm spills over and pulls others in. And Rin? Math is more than just numbers to her. She might seem distant, cool, and all business, but the way she works through each problem with such precision, the way she never leaves a concept half-explained or lets a mistake slide.
Spending all this time with her has made him realize just how much she enjoys what she does. And because of that, he finds himself enjoying it too.
His gaze flickers to the certificates framed neatly on the wall behind her. Ivy League diplomas, awards, achievements. One, in particular, catches his eye— Doctor of Philosophy in Mathematics written in elegant, almost regal lettering. He exhaled softly, smirking to himself. Beauty with brains. A cliché, sure, but standing there in front of him, in the form of Rin Itoshi, it didn’t feel like one. It felt like the most obvious truth in the world.
He notices the way her long lashes fan across her cheekbones, her glossy pink lips uttering things that he couldn't make out in his trance. Shidou has been with plenty of people in his life. He never cared much about the specifics—the way they looked, what they had between their legs. None of that mattered. If someone could make his heart race, if they made him want to immortalize them in the form of something beautiful, something raw– then, as far as he was concerned, he was all theirs.
Rin Itoshi was all of that and more.
She tolerated him, but never let him get away with too much. She knew how to keep him in check without breaking his spirit, challenging him in ways no one else ever had. It was frustrating. It was thrilling. It was hot. Their back-and-forth had become something of a daily ritual, an endless game of push and pull that he never grew tired of. And somehow, without realizing it, waking up in the morning became easier–because he knew he’d see her.
She was his reason to get out of bed. His biggest motivation.
He’s never fallen for someone like her before—so distant, so untouchable, yet utterly captivating. The kind of woman who made him feel like he was constantly chasing, like no matter how close he got, she was always just beyond his reach.
And now, he’s running out of time.
A few more months, and he’ll be gone. Graduated. Out of here for good. He curses himself for not spending more time in the STEM department before now—because if he had, there’s no way he would’ve missed someone like her.
The thought leaves a sharp pang in his chest.
He’ll miss her.
More than that, he wants her.
Badly.
Did she also feel the same towards him? He wanted to push, just a little bit…
The sound of Rin’s pen scratching against the paper fills the quiet office as she marks up Shidou’s work. She barely spares him a glance before muttering, “Stop staring, I won't go over this again– also you got this wrong. Again.”
Shidou, leaning back in his chair with his arms crossed, just smirks. “Maybe I did it on purpose. Just to see how you’d react.”
Rin stops writing, her eyes flicking up to meet his with a flat stare. “That’s the dumbest thing I’ve heard all day.”
He leaned forward, resting an elbow on her desk. “And yet, you’re still here, putting up with me. Almost like you care.”
She exhales sharply, clearly unimpressed. “I care about my students doing their work properly, not about entertaining your idiocy.” But the way she grips her pen just a little tighter tells a different story.
Shidou chuckles, tilting his head. “You always say that, but I bet if I stopped showing up, you’d miss me.”
Rin scoffs, but this time, she doesn’t fire back immediately. He watches her closely, notices the way her fingers twitch slightly before she sets the pen down. “Don’t flatter yourself,” she mutters.
Something about the way she says it—quieter, less sharp,makes Shidou pause. For once, she’s not snapping at him. He shifts closer without thinking, elbows resting on her desk now.
"You’re blushing, Professor," he teases, voice lower than before.
"I am not," she huffs, but she still won’t look at him.
He leans in just a fraction more, close enough to catch the faintest hint of her perfume, his voice almost a whisper now. “You sure about that?”
Rin finally looks at him, her usual cold stare wavering just slightly. For a second, neither of them says anything. The space between them feels smaller, charged. His eyes flicker down to her lips,just for a second,but he knows she catches it.
And for once, she doesn’t pull away.
Just as the tension reaches its peak—
BANG!
The door flies open.
“Ms Itoshi, your meeting–”
Nanase shouted while panting and coming to a stop in the doorway, he seemed to have rushed all the way here to remind her of this.
Rin abruptly moves away from Shidou and stands up still.
“Uh oh–yeah. Thanks for the reminder, Nanase I’ll be there in a minute” her voice coming out just a little too high-pitched. She turns away, fumbling with her stationery, trying to act normal. But the way she nearly knocks over a stack of books and has to catch them at the last second showed that she is very much bothered.
Nanase blinks at her, confused, before his gaze shifts briefly to Shidou, who turns his head toward him and shoots him a death glare.
“EEK-” Nanase squeeks almost comically before making an excuse and running out again.
Rin was too embarrassed to notice any of this taking place before her. She makes her way out only to pause in the doorway, and without turning back to look at him, she says,
“I gotta go.”
“Okay”
After she’s gone, Shidou lets out a slow breath and drops his head onto the desk, his face still burning. Eyes closed, he replays the moment over and over, every detail seared into his mind. The way she leaned in, just a little too close. The flicker of her gaze, hesitating on his lips. The soft flush blooming across her cheeks, a stunning shade of cherry.
He isn’t imagining it. He knows what he saw.
She wants him too.
He’s sure of it.
—
Over the next couple of days, Rin did everything in her power to avoid facing Shidou. She kept her head down during class, pretending to be engrossed in her notes even when she could feel his gaze burning into the side of her face. When he tried to get her attention, she acted as if she hadn’t heard him, her expression carefully neutral, her body language closed off. In the hallways, she clutched her phone to her ear to make it seem like she was busy. If she so much as spotted his familiar figure in the distance, she pivoted on her heel and took the longest route possible to her next destination, even if it meant being late.
But the final blow came the night before their scheduled one-on-one study session. Shidou had been expecting her, waiting for the usual confirmation that she’d be there to help him cram for the upcoming exam. Instead, he received a half-hearted email with no greeting and no punctuation beyond the bare minimum.
"Feeling sick, study on ur own."
No apology. No explanation. Just a blunt dismissal.
Shidou huffs, trying to calm the anger rising within him. Rin Itoshi, how very unprofessional.
—
Shidou walked into the class pretty confident about the test. He sees his professor seated in her seat, and for a brief moment, they make eye contact. And she turns her head so fast one would think she came face to face with a fucking ghost. He exhaled a laugh.
He’ll see how long she can keep running.
The test papers were distributed once it was time. Shidou took a deep breath before reading over the questions.
Huh?
These are pretty different from what he’s worked on till now…
The confidence he held before depleting slightly, he glanced at Rin accusingly. He catches her already looking at him. He frowns, and she feigns indifference, looking away.
Dammit can he even pass this?
—
Shidou was pissed.
Although he managed to get through all the questions on the exam he’s sure he had fucked it up. The cold shoulder from Ms Itoshi, along with a disastrous exam, has left him feeling irritated beyond belief. He was on his way back to the dorm when he sees it.
Ms Itoshi walking down the stairs with a stack of answer papers and following closely behind was Nanase with another set of papers in his hands. He was laughing at something she said, smiling ear to ear like a lovestruck fool.
Shidou’s vision goes red.
No, seriously, he feels like he could rip that bastard in two, medieval torture style.
"What the hell could Rin fucking Itoshi have said that’s got you laughing your ass off like that, huh?!"
It’s pretty obvious Nanase has a big fat fucking crush on her. Shidou felt sick to his stomach as he watched them go about their way. Why is she letting that wuss get all close up in her space like that??
Nanase didn't know what to do with all … that
Only Shidou could.
He wasted no time and didn't care to inform her early because he knew what her response would be. Shidou barged into her office and locked the door behind him. Nobody is gonna interrupt them again.
Rin looked startled, “You!”
Her voice was sharp, but Shidou wasn’t fazed. His frown only darkened as he closed the distance between them, each step deliberate, heavy with purpose.
She was packing up, he caught the sight of her belongings half-tucked into a bag. She was planning to leave.
Not if he had anything to say about it.
He walked closer until they were face to face, he looked her down, voice low, brimming with anger,
“What the hell was that exam, huh?”
Rin raised a brow
“Did you do that deliberately so you could fuck me over? Keep me in your class for one more year?”
Rin looked taken a back by his demeanor, she looked angry at his accusations.
“You think I give enough of a damn about you to pull something like that?” she shot back, crossing her arms. “Get over yourself.”
Her tone was sharp, cutting, but there was an edge of disbelief beneath it, like she couldn’t decide whether to be insulted or amused by the sheer audacity of his accusation.
Rin took a step back on instinct, but Shidou followed, closing the distance between them with slow, deliberate strides. The air in the room grew heavy, charged with something volatile.
A smirk tugged at his lips, but his eyes burned with something far more dangerous. "Oh, you do give a damn about me," he murmured, his voice low, almost taunting. "That’s why you’ve been avoiding me all these days, Prof. I can read you like a book—do you know that?"
Rin’s back hit the wall, her breath hitching for just a fraction of a second. She masked it quickly, tilting her chin up defiantly. "You don’t know shit," she bit out, but there was something uncertain in her voice, something unsteady.
Shidou leaned in, one hand braced against the wall beside her, caging her in. He was too close now, his presence suffocating, intoxicating. His smirk widened.
"That so?" he whispered. "Then why aren’t you looking me in the eye?"
Rin’s eyes widened.
Somewhere in the back of his mind, there was a little voice screaming at him, telling him to stop this and that crossing this line with his professor could get him into serious trouble.
Rin was tall for a woman, but Shidou was still a head taller than she was; her face reached up to his shoulder. Towering over her , she looked so vulnerable, cornered like this. but from where he stood, he could look down and see the beautiful flush of her skin, a warm, beautiful heat blooming from her cheeks, trailing down her neck, disappearing beneath the collar of her shirt. His gaze lingered, dark and curious.
How far did that flush go?
The thought sent a slow, wicked smirk curling onto his lips. He wanted to find out.
He lowered his head down to her neck and breathed in her scent. Something minty and fresh. His nose ghosted over her pulse point and she jerked. He smiled and pecked her there.
“It hurt me a lot that you would do me like this, Prof” He says looking at her face
She finally looks up at him, “This isn't appropriate you have to let me go.”
“Oh yeah? How about this?”, His hand suddenly cupped one of her breasts.
It didn't fit in his hand…Shidou had big fucking hands.
She’s going to be the death of him.
Rin gasped, “Y-you!”
He began fondling her tit, squeezing it over the fabric over her shirt and feeling the outline of her bra. She quirmed in his grasp, letting out small gasps.
“S-stop this I will report you nngh–” sentence cutting off when he pinches her nipple through her bra.
Shidou leaned in, his breath hot against her ear as he whispered, his voice dripping with amusement and something darker. "And what if I let everyone know that the feared math professor has a thing for younger guys? Then what happens, Prof?"
Before she could react, his tongue flicked against the outer shell of her ear, slow and deliberate, sending a shiver down her spine.
His hand stayed planted against the wall, keeping her caged, but his leg—his leg slid between hers, moving with torturous ease. The stretchy fabric of her pencil skirt bunched up inch by inch, the soft drag of it against her thighs making heat coil in her stomach.
Then he found it—the warmth he was searching for. His knee pressed ever so slightly, and his smirk deepened as he felt the proof of her unraveling beneath his touch.
“I dont know what–”
Shidou’s voice was a low, heated drawl against her skin, each syllable dripping with something dangerously possessive. "Have you fucked your spineless little TA yet, Prof? He was practically drooling all over you."
Rin’s eyes blazed with fury, her breath hitching. The sharp slap she aimed at him came without hesitation, a reaction born from both outrage and something she refused to name.
But Shidou was faster.
His fingers closed around her wrist before the impact landed, his grip firm, unyielding. In one swift motion, he yanked her arm above her head, pinning it against the wall. The sudden movement sent her body arching slightly toward him, chest rising and falling with sharp, uneven breaths.
Trapped. Completely at his mercy.
His smirk was slow, wicked. His gaze flickered downward, drinking in the way her pulse thrummed wildly at the base of her throat. He leaned in, their lips nearly brushing.
"What’s wrong, Prof?" he murmured, his voice a dark promise. "Did I hit a nerve?"
She scowled at him, baring her teeth in frustration, looking every bit like a cornered cat—fierce, defiant, utterly adorable.
Shidou couldn’t help the smirk tugging at his lips. So, so cute.
But despite the fire in her glare, her body told a different story.
Slowly, deliberately, she rolled her hips against his thigh, the movement subtle but unmistakable. A silent admission. A challenge.
Shidou exhaled sharply, his grip on her wrist tightening just slightly. He could feel her through the thin fabric of her stalking, the heat of her seeping through, dampening the thick material of his cargos.
His smirk deepened.
"Then what about me? Am I the exception?"
He asked, his lips trailing along the curve of her nape, pressing slow, lingering kisses before sinking his teeth into her skin. He wasn’t gentle, he wanted to mark her, to brand her, to make sure she felt him long after this moment was over.
His free hand moved with deliberate slowness, fingers expertly undoing each button of her blouse, parting the fabric inch by inch. As it slid open, his breath hitched at the sight before him—her full, perfect breasts spilling into view, barely constrained by lace.
He got his answer; the flush of her milky skin reached all the way down to her chest.
Shidou felt like a beast who was presented with a sacrificial lamb. And he was going to devour her whole.
He ran his tongue down her cleavage, warm skin tasted salty like sweat.
She yelped at the contact. her body jolting, but she didn’t pull away.
Still grinding against his thigh, she clung to him, her fingers digging into the hard muscle of his exposed biceps. Her blunt nails left faint crescents in his skin, a silent plea for more, for something deeper.
Shidou smirked against her chest, breath hot as he murmured, “Answer me baby, am I the only exception?”
She moaned at the endearment and it went straight to Shidou’s very hard dick thats begging to be freed.
“D-dont get ahead of yourself … you canvas clown”, She utters with a smug expression resembling that of a cocky feline.
Hah
He’s gonna fuck the shit out of her
“How about we pick up where we left off last time” , He then dives in for her lips, claiming her with a raw, almost desperate hunger. His grip tightened around her waist, pulling her flush against him as his tongue pushed past her lips, demanding, relentless. The kiss was all teeth and heat, bruising and possessive, like he wanted to consume her, like he was staking his claim.His fingers tangled in her hair, tugging just enough to make her gasp, and he swallowed the sound greedily, deepening the kiss until there was no space left between them—just heat, friction, and the undeniable need crackling between them. She moans into his mouth, tears forming in the corner of her eyes from the overwhelming need.
He picked her up by the hips and plopped her on her desk, barely caring about the way the items on top fell to the floor. All that mattered was her —the way her thighs instinctively parted for him, the sharp inhale she took as the cool surface met the heat of her skin.His hands stayed on her, fingers digging into her hips as he pressed in close. He hiked her skirt all the way upto her abdomen, He saw the snail trail in the middle of her stalkings.
With one sharp motion, he ripped the fabric down the middle, the sound of tearing cloth barely registering over Rin’s startled gasp.
Before she could react, he was already on his knees, face pressed between her thighs, right where her now-exposed thong clung to her heat. He inhaled deeply, dragging his nose up along the damp fabric, savoring the intoxicating scent of her arousal until it flooded his senses, making his pulse hammer.
His fingers curled around the thin material, tugging it aside with a deliberate slowness, revealing her glistening pussy to his hungry gaze. A low, satisfied growl rumbled from his throat as he tilted his head up, smirking.
"So fucking wet for me already, baby"
He didnt waste a second before his tongue swiped across her cunt. The cool steel of his tongue piercing making contact with her clit drawing out a high pitched moan out of her.
“Aaahh–”
Her fingers instinctively tangled in his hair, nails scraping against his scalp as if trying to ground herself, but Shidou only smirked against her, enjoying the way her thighs twitched, the way her body arched as he flicked his tongue over her swollen bud again—this time pressing the metal against her just a little harder, just to watch her break.
Shidou could eat her out for hours , he loved pussy, loved the taste, the smell, the way delicate lips parted for him like a beautiful butterfly. Rin had a mouth watering cunt, her pink insides were dripping their honey onto his lips and he slurped it all up like his life depended on it.
He thrusted his tongue inside and watched her squirm around him. Thighs tightening around his head keeping him buried in her heat. Good. She wasn’t going anywhere until he had her trembling and wrecked beneath him.
He smirked against her, dragging his tongue up to circle her clit before flicking the cool metal of his piercing against it. The jolt that ran through her body made his cock throb.
"Sensitive, aren’t you?" he murmured, voice muffled by her heat.
Rin whimpered, her fingers yanking at his hair, half in desperation, half in an attempt to slow him down—but he wasn’t going to. He wanted her undone.
Sliding two fingers inside her, he curled them just right, pressing against that soft, spongy spot that made her cry out. His tongue worked in tandem, rolling and flicking over her aching clit, his fingers pumping faster, harder, soaking up every moan, every shiver, every tiny plea she refused to say out loud.
Her breathing turned ragged, her thighs quivering against his cheeks, and he could feel her getting closer—her walls tightening, her hips bucking against his face, chasing that final high.
"C’mon, Prof," he taunted, voice dark and sinful, "Give it to me. Let me feel you come all over my fingers."
And then he sucked her clit into his mouth, swirling his tongue over it while his fingers fucked her relentlessly, sending her spiraling over the edge.
She shattered. A sharp, broken cry tore from her lips as her back arched off the desk, her body convulsing, her cunt clenching down around his fingers as she came, coating his fingers with her creamy release.
He pulled out his digits from her insides and stared at them, smiling to himself he licks it up while looking down on Rin who looks appalled by his action.
He have to be inside of her any minute or else he’s gonna burst and thats not something shidou’s pride will let him endure.
So he undoes his fly and pulls out his cock, that stands up majestically in all it’s studded glory.
Rin lifted her head up to look down at it, she looks mortified, it reached upto her belly button and it had shiny piercings on the underside of the shaft near the head.
“Like what you see? Heh its a frenum piercing.” he says smiling proudly.”Im gonna take you to heaven baby”
He then aligns it against her entrance.
“W-wait! I dont think I can–”, her words died down when he pushes his head in.
Rin’s head falls back and she moaned so beautifully
She begs him, “Nnnghh please Im not- I cant- pleaahh wear cond–”
He then slams the entire shaft all the way in.
Rin sees stars behind her eyes.
Her walls squeezed him tight, pulsing around him like they were trying to pull him deeper.
Shidou groaned, leaning down until his lips brushed her ear, voice thick and heavy with lust.
"Told you, Prof. I’m taking you to heaven."
And then he started to move.
He pulled all the way back, but a sudden knock echoed from the door.
"Professor Rin? Are you alright?"
Rin's eyes flew open in panic. Nanase.
Shidou’s eyes filled with an evil glint, looking down at her in amusement at the way she suddenly clenched around the head.
Dont you dare her expression seemed to say back to him.
Shidou, being the absolute menace he is, thrust back into her in an instant, sheathing himself deep inside of her. Rin covered her mouth with her hands, tears dripping down her face.
"I—I'm fine!" she managed somehow.
"Are you sure? You sound kinda—"
Shidou grinned against her skin and, without warning, pulled all the way out till his head kissed her entrance. Rin thinks she’ll lose her damn mind if this carries on.
“Im okay! w-why are you here? she gasped, voice cracking mid-sentence.
Nanase, oblivious to the absolute filth happening behind this door, hummed thoughtfully.
“Oh i just wanted to tell you i have finished correcting all the papers and the grades will be posted by evening.” Right then, Shidou slammed back in, deep and deliberate, pressing against every sensitive spot inside her.
Rin let out a strangled, muffled whimper, gripping onto the desk for dear life.
"T-thanks, Nanase!" she forced out, voice an octave too high, too breathless to sound natural.
Shidou fucking laughed against her shoulder, his breath hot as he thrust even deeper, rolling his hips in slow, measured strokes meant to make her suffer.
"Alright then, have a good rest of your day, Professor!"
Nanase’s retreating footsteps were the last thing Rin heard before Shidou’s teeth sank into the curve of her neck, and he picked up the pace.
"Now, where were we?" he murmured darkly, dragging his cock against her overstimulated walls, completely unbothered.
Shidou fucked the way he did everything else—with relentless passion, reckless abandon, and a primal hunger that knew no restraint.
He pulled out and slammed back in like a fucking machine powered by a 7000 horsepower engine. The desk creaked beneath them, Rin tried her fucking best to muffle her moans using both her palms but the way Shidou’s cock keeps knocking her insides, his studs rubbing against her walls so perfectly she doesnt think she can hold out for long.
She’s certain, in the 36 years she’s walked on this earth nobody, not a single soul has fucked her like this
Her breasts had spilled free from her bra, bouncing with every deep thrust, moving to the rhythm he controlled. He was mesmerized, utterly hypnotized by the way her body responded to him.
Unable to resist, he leaned down and latched onto a pert, pink nipple, rolling his tongue over the sensitive bud before biting down just enough to make her gasp. His other hand found her neglected breast, kneading and pinching, teasing her until she was squirming beneath him.
She shrieked at the sudden sensation, her back arching so beautifully, offering herself up to him like she was made for this.
“You know, when I saw you for the first time, all I wanted was to bend you over on that desk and take you in front of everyone,” Shidou says in her ears, still stroking into her.
She clenches tight around him at that.
Shidou whimpers in her ear, he can feel himself reaching his limit.
“Would you like that Professor?”, Shidou could feel her tightening around him, her body responding to every filthy, deliberate thrust like she was made for this. For him.
He rolled his hips, slow and deep, forcing her to feel every inch as he stretched her open. Her head thrashed against the desk, a strangled whimper escaping her lips.
"That’s it. Let me hear you." He licked a hot stripe along her throat, feeling the frantic pulse beneath his tongue. "No point acting all high and mighty now. Not when you're dripping all over my cock like this."
Rin squeezed her eyes shut, her breath hitching as he snapped his hips forward—sharp, relentless, hitting that spot over and over until her legs shook around his waist.
"Tell me, Prof," he murmured against her lips, thrusting slow, deep, teasing her with every withdrawal. "Who’s the only one who can fuck you like this?"
She refused to answer, lips parted, barely able to breathe through the pleasure.
Shidou’s grin turned wicked.
"Let’s see how long you last before you’re screaming my name."
"Still holding out on me, huh?" he murmured, his voice dripping with dark amusement. He pulled out almost completely, leaving her aching, empty, before slamming back in, hard and deep.
"Shidou—!" Rin gasped, her back arching off the desk, hands flying to his shoulders for support.
"Tsk tsk," he groaned, picking up the pace, fucking into her with brutal precision. "Call me by first name."
She bit her lip, trying to fight it, trying to hold onto whatever shred of dignity she had left, but Shidou wasn’t having it.
He angled his hips just right, hitting that perfect spot, the one that had her thighs tightening around him, her breath stuttering.
"Ryusei—ah! F-fuck!" she cried out, her nails digging into his skin, her entire body shaking with the force of it.
"There we go," he growled, grinning like the absolute menace he was. "Knew you had it in you. Scream it for me, Prof. Let the whole damn building know who’s fucking you like this."
"Ryusei! Oh—God, Ryu!" she sobbed, her walls clamping down around him so tight, so perfect, so fucking desperate.
Shidou groaned, riding her through it, not stopping, not slowing down.
"Fuck, you’re perfect," he panted, watching her completely unravel beneath him. "And you’re all mine."
He comes deep inside her splurting until he falls on top of her exhausted.
Shidou leaned back, still buried deep inside her, taking in the wrecked, fucked-out mess beneath him. Rin’s body was glowing with sweat, her chest rising and falling in uneven breaths, her legs still wrapped weakly around his waist.
He reached for his phone, grinning like the absolute bastard he was, and snapped a photo—Rin spread out on her desk, her skin flushed, her expression dazed and ruined.
"Gotta keep a souvenir," he murmured, thumb stroking over her swollen lips.
But just as he was admiring his handiwork, his phone buzzed with a notification.
Exam grades posted - Nanase Nijiro (TA, MATHEMATICS)
Fuck
He clicked on it and he couldn't believe his eyes, 82%. For a second, his brain refused to process it. All that stress, all the frustration, all the damn time he spent cursing Rin’s name, thinking she’d rigged the exam to screw him over—
And he actually passed?
Shidou smirked down at her, shaking his head. "You really had me thinking you failed me on purpose, Prof." He tapped his phone screen, flashing the grade at her. " 82. You actually let me pass."
Rin rolled her eyes, still breathless. "I told you I wasn’t out to get you, dumbass."
Shidou clicked his tongue, tossing his phone onto the desk. Then, without warning, he leaned down, lips brushing her ear.
"Tch. And here I was, thinking I’d have to fuck an A+ out of you."
Rin barely had a second to react before he snapped his hips forward again, sinking back into her overstimulated heat.
"Ngh—Shidou! You—!"
He grinned, voice dark and teasing. "Too late, Prof. You still owe me for the mental trauma."