Chapter Text
Zenitsu often asked ‘What type of man are you?’
Tanjiro had always been a bit confused when he asked, so Zenitsu would just grin, and tilt his head toward a pair of omegas passing by. “Boobs or butt?”
Tanjiro would inevitably blush, and declare that Zenitsu was disgusting for objectifying omegas so casually.
Zenitsu had been among the first in their class to present as an alpha, presenting at 12, and he seemed to think that warranted him some type of respect.
Tanjiro, on the other hand, had been deadlast by a fairly wide margin. His parents had even taken him to a doctor to see if there was something wrong with him, but the doctor could find nothing. Tanjiro was just the latest of late bloomers.
His special circ*mstances led Tanjiro to have to use the locker rooms last when getting ready for Kendo Club. After middle school, there were no gender neutral toilets or changing rooms for him to use, so he’d been instructed to use the Omegas’ for safety purposes.
If he suddenly presented as an omega while using the alphas’ locker rooms…
Well. That just would not fly.
But, that led to the alternative. Tanjiro presenting as an alpha in the omegas’ locker room.
A situation that, unfortunately, did happen.
Just before Tanjiro entered, a gaggle of omegas exited, each one freshly showered after the last gym class of the day. It was time for extracurriculars, so they said their pleasantries to Tanjiro and waved farewell.
Tanjiro made sure the room was empty, breathing a sigh of relief when he saw that the coast was clear, and he began to change out of his uniform and into his kendo outfit.
He threw aside his uniform cardigan, aiming for the open locker but falling short. He rushed, hoping to not get it wet from the girls’ leftover puddles, when he froze.
His nose twitched when he was bent over, holding his sweater. He fell to his hands and knees, seeking the scent.
It was in the locked locker just in front of where the sweater had fallen. Tanjiro tried to open it, but it refused entry. He slammed his fist against it, causing dents in the metal and bruising on his hands, but still it refused.
Reason did not reach Tanjiro’s higher mind as he tried, in vain, to get to whatever that sweet, heavenly scent was. He didn’t notice when his Kendo teacher Urokodaki-sensei came rushing in, nor when he grabbed Tanjiro and pinned him to the tile. Tanjiro snarled, struggling against the surprisingly strong old man.
He came to when he was in the school's infirmary, breathing heavily as he jolted upright in alarm, feeling a distinct pain in his outer thigh. “W-what happened?! Urokodaki-sensei?!”
“Congratulations,” He heard the school nurse say. She was at her desk not far from his bed. “You’ve officially presented as an alpha.”
“I...uh...oh…” Tanjiro said smartly, swallowing hard. “I suppose...that’s a good thing, huh?”
“Well, in a sense.” the nurse hummed. “You don’t seem too happy about it, is there a reason?”
“I just...I’d been operating under the idea I’d be an omega,” Tanjiro said, breathing out a deep sigh. A good few thousand hours of day dreaming of becoming a bride, carrying a child and being the atriarch of his own, big family someday essentially put to waste.
“I’m sorry to hear your results were unfavorable,” she said, genuinely sounding sympathetic. “But, reality is reality. Your first rut was stalled by an injection I gave you, it should last until you get home. There’s some scent patches on the bedside for you, please apply them in the bathroom.”
Right, patches. Tanjiro glanced and saw the package, picking it up.
“You’ll have to go on suppressants as soon as your rut is finished, but your parents can take you to your family practitioner for that.” The nurse continued as Tanjiro made his way to the infirmary toilet. “And please hurry home, that injection should only last for about an hour and a half.”
Oof. With Tanjiro’s usual commute, that would be cutting it close. On a good day he could get to and from school in an hour and 10 minutes, worse days were closer to two full hours if the trains were busy.
Well, he just had to really rush it then.
He pulled out the patches, large white band-aid looking things that smelled very strongly medicated, and read the instructions.
Clean scent gland areas with wipes provided with the packaging (Scent gland areas: nape of neck, collar bone area, upper shoulder blades, upper rib cage just beneath the armpit, lower back, inner thighs and the space between belly button and pubic area), unpeel and attach scent patches as the picture directed.
Tanjiro winced slightly as he undid the first patch. They were definitely going to hurt when he had to peel them off later. Each patch for each area was shaped slightly differently, and Tanjiro was fairly certain he mixed up a couple.
Hopefully it didn’t matter.
The nurse also sent him out with a clear silicone onahole and a small bottle of lube, which was all kinds of horrifying to accept. (Thankfully, she gave it to him in a black cloth pull string bag so he wasn’t walking around the school halls with a sex toy in hand.)
Tanjiro collected his things, said his apologies to Urokodaki-sensei, and made his way to the train station.
He made it through the first half hour alright, switching trains when he needed to, listening to his music and tuning out the insistent heat he was starting to feel under his skin.
But, as time went on, he started feeling worse and worse. The light heat began to ramp up, his chest ached like he wasn’t getting enough air, causing him to breathe heavier. He had to clench his teeth to force himself to not pant like a dog. Then, an itch began underneath the thigh patches, and he wanted so badly to scratch it, but he did not want his hand anywhere near his crotch right now, so he started bouncing his leg up and down.
Then, he got on the train.
Possibly the most beautiful Omega Tanjiro had ever seen. Long, inky black hair tied back into a messy low ponytail, a red plaid skirt that barely covered his round, bouncy ass, an unbuttoned navy blazer that showed the crisp white button up shirt underneath, with the buttons themselves straining to keep closed with the size of his bust. The cloth of his button up was so, so thin, Tanjiro could almost make out the lace of his bra. He was also wearing a neck bow made of the same plaid as his skirt, just barely hiding a scent blocking collar that seemed intentionally loose so as to let some of his sweet, oceanic scent just barely make itself known.
But, Tanjiro’s eyes were also drawn to something else. His thighs .
Clad only in tall, black thigh high socks, Tanjiro could see, very clearly, the yielding thickness and muscle of his thighs. There was a bit of plush, the tight upper hem of the sock squeezing down on flesh and causing the slightest muffin top, and god did Tanjiro want to press his fingers into that soft, porcelain skin to see how soft they really were.
Tanjiro knew by the tightness that the elastic had to have left some indentation, and Tanjiro could very much help soothe the pain that came with taking them off! He knew he could! He’d never done it before, but he had a feeling instinct would carry him.
Tanjiro could very much understand Zenitsu’s question now. He could tell his friend that, no, he was not a boobs or a butt man, he was a thigh man!
The thought of telling Zenitsu his little revelation brought him back to reality in sharp relief.
He’d been unabashedly staring at the omega for the better part of the last ten minutes, his leg bouncing stopping when he’d popped possibly the most embarrassing boner of his life, thankfully hidden by the bookbag in his lap. He stared down at his feet, face beat red as he scolded himself internally.
All that talk about objectifying omegas and here he was, drooling over a stranger and thinking about thighs! He was a shameful alpha.
He tried to keep that thought in his head, eyes closed as he breathed shallowly, trying to not get as much of the omegas’ scent into his nose as possible. He’d switch trains, leave the pretty omega alone and make his way home.
He’d probably fantasize about him in his rut, but he’d deal with that shame when he got to it.
They were getting to the next stop. People filed out. The pretty omega didn't.
Tanjiro felt his sweat gathering, and the scent patches unsticking themselves. He held a hand to his neck, forcing it back down. The sweet omegan scent grew stronger, and when Tanjiro’s eyes opened, he saw black-clad legs.
He looked up, and saw the omega staring down at him, brows knit and lips in a thin, displeased line. “Kid, don’t you know it’s dangerous to be walking around when you’re in a rut?”
“I-i...I just….presented a-and I’m almost home, I-I didn’t…” Tanjiro stammered, his eyes wide. The omega’s face was just as beautiful as his body. Cerulean blue eyes, bangs framing his face, a thin, angled nose and plush, pretty lips, lightly glossed.
“Which station is ‘home’?” He asked.
“Uhm...Kumotori Station…”
The omega sighed, hand on his hip. “That’s too far. Your pheromones are too strong, you’re going to start a revelry if you keep going.”
“A...revelry?” Tanjiro asked, confused.
The omega leaned down to whisper in his ear. Tanjiro almost didn’t hear him with how hard his heart was beating, being so close to the omega’s half-assed collared neck. “It’s when a bunch of people in a closed place, like a train, all fall into heats and ruts at the same time and f*ck. Horny ass teenagers who forget their suppressants can send entire crowds into a goddamn orgy. Don’t they teach you this in school?”
If they did, Tanjiro had likely been excused from the lesson because of his super late presentation.
“I-I didn’t know! Wh-what do I do?! I-” Tanjiro asked, alarmed. He looked around, eyes widening further when he realized that everyone else on the train was holding hands and hankies to their noses, noticeably angling themselves away from him.
The train even seemed less crowded, like a bunch of people got off when Tanjiro’s patches had loosened.
The omega sighed. “Guess there’s no other option. You said you’d just presented, right? How old are you?”
“I...uhm...f-fifteen?”
The omega’s eyebrow went up in question. “fifteen? That’s really late for a presentation.”
Tanjiro didn’t want to admit he was only a few months away from fifteen, it made his lateness even worse. “I-I know…”
“Fine, fiftteen. I think God will forgive me for fiftteen.”
“W-what?” Tanjiro blinked, confused.
“Get off this train with me at the next stop,” The omega said. “There’s a love hotel not far from there, you can spend your first rut with me and be back before the trains stop for the night and you’ll be back home in time for dinner.”
“I...w-would that...really be okay…?” Tanjiro asked, gripping his bag tighter to him.
“It’s either that or I read about a fifteen year old criminally charged for starting a revelry in the newspaper tomorrow,” The omega scoffed. “Your choice.”
Tanjiro whimpered, eyes closing. “Then...o-okay, I accept your offe- A-ahhahh~” Tanjiro gasped, arms flying up like he was surrendering as the omega placed his sock-covered knee onto the seat between Tanjiro’s thighs. He put it right up against his crotch half hidden by Tanjiro’s bag he’d been keeping in his lap.
“Hmph. Good choice.”
“K...Kamado Tanjiro,” Tanjiro sputtered out, his face bright red as the train made the omega’s knee grind up against his crotch. “M-my name is K-Kamado Tanjiro.”
“Giyu.” The omega said, offering no family name. “I saw you staring at me, you little perv,” Giyu hummed, his arms resting on Tanjiro’s shoulders. “You were getting all hot and bothered seeing me in my uniform, weren’t you?”
“I-I’m s-sorry!” Tanjiro squeaked as the omega’s knee brushed up against his painful hardon. “I didn't meant t-to stare..."
Giyu seemed unimpressed by the teenagers’ apology. He grabbed Tanjiro’s raised hand, pulling it and slapping it onto his thigh. “Keep yourself busy, we still have 15 more minutes till the next stop. Just keep those fingers out of my panties for now.”
Any self control or shame Tanjiro possessed almost immediately evaporated when his fingers made contact with skin. In full view of everyone on the train, he started groping Giyu’s thighs, both hands sliding up and down his socked legs. His fingertips dipped into the elastic, wrinkling the perfect smoothness, and he felt the edges of Giyu’s own scent patches.
“You looked so innocent and cute,” Giyu chuckled above him. Tanjiro had his nose stuffed in Giyu’s belly as he felt up those thick, beautiful thighs, grabbing a handful of pert, round ass beneath Giyu’s plaid skirt. His hands were too small, he could only grope so much. “Look at you now. You look like you could cum just from humping my leg. You really are a virgin, aren’t you?”
Tanjiro’s body trembled. He breathed out into Giyu’s tummy, feeling the ache and tension in his body slowly ebb away now that his newfound sex drive had a target. His heart sang and ears rang as he listened, the heated feeling of embarrassment and humiliation only driving his hips to grind harder into Giyu’s knee.
Giyu was opening up something in Tanjiro that would be incredibly hard, if not outright impossible, to close again.
