Work Header

The Number One Oiran

Chapter Text

On a quiet night was born a small healthy boy to a brown-haired woman in the Shinjuku district. The child had the same lovely brown eyes and brown hair as the woman.

On that night, Zenitsu was born. 


His mother worked as a prostitute in Yoshiwara, even before Zenitsu was born. Fortunately, the brothel that she worked for took care of Zenitsu like they were family. The brothel itself was one that took in girls from poverty or abuse and had no skills or use in life other than having a slightly pretty face. 

Zenitsu was a crybaby too, he'd cry at the smallest things, like the flicker of the light or the storm outside. He grew up to be one too. To no one's surprise, Zenitsu presented as an omega at 7.

The yujo in the shop pampered him with small trinkets they would get from the customers, like a hairpin or a ring. Hachi, one of the older yujos, would always give him a candy.

Zenitsu collects most of these trinkets and keeps it in the pocket of his small yukata. He'll say goodbye to the yujos and the Oiran-onee-sama and then he'll turn to his mother to give her a big hug. Show her what the women gave him and then chatter away about how pretty it is.

His mother, contrary to the usual prostitute, could read and write. She taught Zenitsu at a young age; he soaked his mother's teachings like a sponge and at 8 the beautiful Oiran-onee-sama took him in as her kamuro.

He'd be allowed to stay with his mother's embrace after every training as he was a bright child. Taking the calligraphy and flower arrangement lessons with ease.

He'd never told anyone but he had really sensitive ears, he could hear the heartbeat of every person and he could hear what they had said even though he was asleep. Each and everyone he had met had a certain sound to them, his favorite one is his mother's. The gentle breeze passing through the trees, the peace of a still lake; that was how his mother sounded like. Like the tranquil of nature.

He likes the sound of Nuyo-sama (the name of Oiran-onee-sama, as he'd discovered) too. Elegance in each of her steps and he could hear her proudness in her job but his most favorite is still his mother's.

So he sleeps in the hold of his mother, her scent of fresh pine reminding him of spring.


When Zenitsu hits puberty, his body starts developing to that of an extremely fertile omega. For some reason, Miyu and Shina- his fellow kamuro- become extremely protective of him. He thinks it's because omegas are rare in the red light district, male omegas close to nonexistent.

He understands that he could be somewhere else other than the red light district but he looks at his family, his mother, the yarita babaa of the tea house, Nuyo-sama and Miyu and Shina and all the other yujos, and thinks that he wouldn't be anywhere else in the world.

At the age of 13, Zenitsu gets struck by lightning. He reaches out for the peaches by the window and an unexpected thunderstorm on catches him by surprise. 

His hair color changes from a chocolate brown to exquisite blond. The next day he moves up and becomes a furisode shinzou, one step closer to an Oiran.

Zenitsu polishes his hearing and learns four new instruments (koto, shamisen, tsuzumi, and shakuhachi) without batting an eyelash. He starts playing for the guest rooms. It boosts his position up.

By 15, Zenitsu becomes a full-fledged Oiran in one of the brothels of Yoshiwara.


"Zenitsu-kun, your first customer is here!" Hana calls him. She's one of the assistants in the tea house. Sweat forms on Zenitsu's palms.

He was ready for this, he'd grown up with the teachings of his mother and Nuyo-sama and he'd be called with a sama suffix too shortly.

"Hana-chan! Can I please, please, please not go?? Tell him I'm sick or something!" Obviously, Zenitsu was not ready.

"It's the third day, isn't it? You can do it!" Hana encourages, then she puts her hand up to her mouth and does a back and forth motion, "You can always resort to this if you really can't."

Zenitsu blushes the shade of a tomato, "You're not helping!"

Laughter bursts out from the girl, "You'll be fine! Most nobles are pretty restrained anyway." 

"Most! But not all! What if he's some really weird person with really weird tastes! I don't want to lose my virginity to someone weird!!"

"Zenitsu!" The loud voice of the owner of the teahouse called. Zenitsu stiffens.

"I'm going to die, I'm going to die in the middle of sex!" He wails.

"Stop worrying! Get to it! Don't waste the effort I put on you!" Hana pulls his hand to get him to the door.


The customer inside doesn't question the happenings in the tea house and quietly waits for the young Oiran, surely someone who's not causing a loud ruckus like the boy outside.


Chapter Text

Zenitsu enters the room with freshly squeezed tears, his heart thumping, his hands clamming up. Tea- Tea ceremony first, he thinks and Zenitsu, with a practiced elegance, pours the tea for his customer.

The man in the other side is the son of a sake brewery. An alpha of great importance in the economic industry of the Taisho period.

He picks up the fan, unfurling it slightly. Slowly gazing up at the man with what he thinks would be a seductive gaze, the slow bat of his eyelash making his customer gasp.

Yes! I'm making progress! A beat and then, No, I don't want to!

Tears well up in his eyes but he tries to hide them as he couldn't show this side of him to a customer. Nuyo-sama would be mad at him if he somehow sullies the name of the tea house. He's an Oiran now!

He can do this, hopefully.

He slowly takes off the intricate kimono and suddenly the man stands up.

The man sees the tear stained eyes of the young Oiran and in a flash of his conscience, decides that he should not partake in the throes of pleasure with such a young boy.

"Zenitsu-sama!" Sama, it echoes in his head. This person is clearly much more older than him and holds some form of superiority over others yet he calls him sama.

It sounds wrong.

"I'd like to court you properly first!" There's clattering in the room, money is laid down on the table and the man exits leaving a disheveled and bewildered Zenitsu.



"So how was it?"

"I... got deserted?"



The following day, he gets sent flowers. It's so atrocious with its overwhelming colors and eye swearing arrangement. He wonders who bought it and from where.

"Kiyo-chan! I don't want this! What if it has poison! Who did it even come from!" He grabs the nearest yujo and flings it to her.

Kiyo smacks Zenitsu, "It's from your customer, stupid!"

He has no choice but to accept the flowers.

Zenitsu, who practiced flower arrangement since his childhood, hates it because it looks incredibly unsightly so he begrudgingly fixes the flowers.



This happens a few more times. Every one of his customers leave at their third meeting.

Zenitsu thinks it's normal and that most Oirans are pure and untainted. It's best for him in that case, he's still only 16 after all.

He hears of the destruction caused on the other side of the district. As much as he'd like to feel pity, that meant more money for them.



Miyu struggles with her shamisen playing, each note on the instrument sounding different from the original. It sounds horrible.

"Like this, Miyu-chan," Zenitsu picks up the bachi and strums, his fingers quickly flying back and forth on the bridges.

The sound filters in the room and Shina, who just came back from tending a customer, listens intently to the sweet sound. Miyu is completely engrossed in Zenitsu's playing rather than studying his movements.

They end the session with Miyu learning nothing and Shina fast asleep on the tatami mat.

Zenitsu doesn't give up though, he drills the shamisen lessons through Miyu's head until she can play for the guest rooms.

Soon, both Shina and Miyu are Oirans too. Nuyo-sama looks so proud to have raised the three of them.

"This old lady can finally retire from being an Oiran without worrying for the future," she says. Zenitsu wonders why.

She becomes the main seamstress in the brothel and their clothes are much more grander than the rest.



One day, Zenistu overhears a conversation.

"Hey, Miyu so how was he?" Shina asks Miyu, as she looks tired but happy.

"The best," Miyu smirks at Shina.

"It was sooo big," she continues.

Shina hmphs, "Size this, size that, what use is it without technique?"

"You're just jealous you always get the small ones," Miyu counters.

"Of course someone like you who only wants the girth would say that!"

"Isn't that what gives the most pleasure?!"

"Obviously you haven't tasted the kind of sex that leaves you absolutely breathless!"

The two girls argue about what Zenitsu couldn't even begin fathom, he gets closer to them to intervene but he gets asked a seemingly harmless question.

"Zenitsu-kun! How do you like your customers?!"

He blinks, "...with lots of money?"

Miyu facepalms; Shina groans, "How big do you want them? Rough or not? What position? Quick and dirty or slow and caring?"


"Dick! We're talking about how you like to take dick!"

"...I haven't?"

"You're the most called Oiran in our brothel! What do you mean you haven't!"

"Isn't it normal?"




He was an Oiran, a sex worker. Now that he thinks about it isn't he the most called out of all three of them? How come he's still a virgin?

Oirans work in both entertainment and sex! If Miyu, who's younger than him by a year already got some, then why hasn't he?! Is he unattractive? Was there some connection it made to customers suddenly sending him flowers right after their third meeting?

Maybe that was normal as a male omega. Would one be seen as a stain if they were to mate with a male omega.

Hopefully it was only that.

Zenitsu forgets that male omegas were valued like gems especially in an industry such as this.



Zenitsu is crowned the unofficial most popular Oiran in the district of Yoshiwara.

In contrary to his position though, he gets more and more envious of Shina and Miyu! What's with their constant talk about customer flow and great sex! He was an Oiran too and he didn't even have sex yet!

How come?! Was he going to die a virgin!

He was the most sought out yet he's still pure!!



Zenitsu is 18 and has just passed his coming of age ceremony. He feels his first heat getting closer and closer.

His current customer was blushing madly at his appearance, although he was teary eyed and looked pitiful in the eyes of his customer, he'll definitely lose his V card today.

However, the customer gets out of the situation just when Zenitsu was about to disrobe the man.

He's left frustrated and confused by another one of his customers who still pay handsomely despite not getting what they came for in the first place.

Shina eyes him worriedly, "It's okay Zenitsu-kun."

"You're still the most popular anyway!" Miyu cheers.

Zenitsu takes in a deep breathe, "You're right Miyu-chan, Shina-chan but..."

"I just want to have some dick too! Is that too much to ask!!"



Frustrated, Zenitsu looks around the tea house for the sound of water flowing by. It reminds him of his his mother, who now works at a different place as a courtesan, calming him down.

There were a series of cases where the customers of Oirans suddenly disappear, leaving the mass wary of the red-light district, especially him since he's the most popular one and is somehow therefore linked to the disappearance.

There might be a murderer who targets Oiran regulars, but then, why? Thankfully, none of Zenitsu's customers have been targeted... yet.

And so his biggest concern right now was still on how to lose his virginity.

He asks Miyu and Shina tips on seduction, noting down each word. Just as how he's done when they were struggling with the instruments.

Zenitsu, with a new found determination, swears he'll lose his purity with his next customer. No matter how they look or smell or sound like!



Tanjirou sweeps his eyes over the red light district, this was a different part from the one where they had met the Upper Moon 6.

It's been three years since Nezuko had turned back into a human and Kibutsuji Muzen had passed, the demons slowly dwindling to countable numbers. They earn a new ability that allows them to propagate their species, however it is completely unstable, the resulting demons from the exchange of blood from the non Kibutsuji demons are weak and would die off in a day.

He'd been promoted to a pillar too, Sun pillar and by some extension the Water pillar. Although Tanjirou thinks Giyu-san is still the perfect one for that spot.

The demon in his case was one who attacked customers of Oiran. Of course, what better way to sniff out the demon other than become a customer himself.

Although there was a long and arduous process of being able to meet an Oiran, he had the money, plus he's curious to meet one anyway.

Tanjirou wouldn't touch them, he just wants to see the extent of their beauty and abilities! There was a reason they were so increasingly popular nowadays.

The tea house he happened to enter was the one where Zenitsu was staying.

At first, Zenitsu thought he thought he was dreaming. There was a hunk of an alpha who sounds so gentle and kind, it makes him want to cry.

Like the sound of mornings when he just woke up, the sparrows singing him a tune or at night when the quietness enveloped him and one can only hear chirping. He sounds something like true love.

Mate. His instincts call.

He'll definitely take this one as his customer!

A few days pass and Tanjirou is considered a regular at the store. The staff had loved him the first time he showed up but he'd wanted to secure that he'd be able to get their most popular Oiran.

And finally their first meeting takes place. Tanjirou, absentmindedly enters the room. The demon attacks at the third day, there was no way he'd be in danger now, and even so he's prepared to unsheathe his sword any moment. There was no chances of him getting eaten.

Zenitsu, on the other hand, had plans to lose his virginity today. Fuck the rules, like hell he'd follow it!

There was a strong and kind and gentle alpha who towered over him and he'd definitely give him the best first time ever!!

Even Miyu and Shina was envious he'd manage to snag him!

Poor Tanjirou had no idea he was already getting eaten in Zenitsu's daydream.



As Tanjirou knows the process of hiring an Oiran, he's surprised the person speaks up to him first.

"Esteemed customer," he drawls, Tanjirou smells the small boy as an omega and his instincts wail at him. Yours.

"I'll perform the tea ceremony now," the blond moves forward and picks up the teapot.

He was the epitome of elegance and beauty. His hair a bright yellow, golden, like the sun. He smelled like peach blossoms and funnily enough, purity and eagerness.

This Oiran was the most popular one yet also a virgin? What a curious case. Just like him, when he was younger. A demon slayer that traveled with a demon. He lets out a snicker.

"Tanjirou-dono?" Zenitsu stopped, did the alpha just snicker? The nerve!

"Ah, don't mind me, you're just really pretty. It makes me happy you're the one who's serving me," Tanjirou says.

It's embarrassing and corny but he blushes anyway. Zenitsu only hears the truth come out of Tanjirou's mouth and it makes him all fuzzy inside.

He doesn't realize he's staring at Tanjirou until he feels a hand stroking his head.

"You're really cute!" He says.

Zenitsu feels his whole body burn bright red. He slowly moves his body closer to the alpha. They'll be touching soon and then it'll lead to—

Yet the moment is cut when the younger man turns his head, looking at one of the side of the room. He hears something weird too, some scratching, an irregular heartbeat. Something sinister and inhumane.

A gruesome figure is out in the open. It's limbs twisted and disgusted. It starts to reach out for Zenitsu but its hand is slashed.

"Stay here," Tanjirou commands the young Oiran.

The demon makes blows a hole in the wall and tries to escape, it's fast but Tanjirou wouldn't be a pillar if he wasn't faster.

In a split second he beheads the demon.

Zenitsu stares, his original smell of peaches and warmth is gone and is turned sour by the fear and somehow there's the faint smell of lightning.

And then he smells of relief. Tanjirou's olfactory senses are filled with the addicting smell of Zenitsu. Maybe he could take him as his wife? Tanjirou jokes with himself.

He laughs at the thought, a person this beautiful would definitely have someone else in mind.

Zenitsu was observably not okay. He almost got a heart attack from seeing the demon pop out. But he's safe, safe, safe.

Tanjirou makes him feel safe, he offers the smell and sound of strength. He was so strong, to have finished off that creature without even as much a single drop of sweat.

In front of him, Tanjirou smiles and Zenitsu couldn't remember seeing anything as beautiful as the scene right now.

Tanjirou has power but he looks so stupid and lovable with that smile on his face, he has the brightness of the sun. And Zenitsu doesn't know if he can live a day without this much warmth. His warmth.

So he does the most logical thing and shouts what's been on his mind since the first time he'd seen Tanjirou.

"Will you please be the one to impregnate me?!"




Chapter Text

In his humble defense, Tanjirou didn't think someone, much less a male omega, would jump him in their first meeting.

When the residents of the tea house heard the Oiran's outburst, they immediately moved them to a different room. They thanked Tanjirou for his efforts and told him to get his prize.

It wasn't until the Oiran started taking off his clothes that Tanjirou realized he was serious with his proposition a while ago.

"What are you doing?!" He shouts, no way was he doing this, his job here was done! In a second the crow would direct him to a new mission and he'd be off to a different place.

Said crow was perched a nearby post, he thought it would be considerate of him if he'd let his master unwind a little.

He cries out, "I don't even know your name!"

"You're kind, Tanjirou-dono," the Oiran looks up at him, "My name is Agatsuma Zenitsu."

His pheromones become stronger, he whimpers, his sense of smell was amped up to the point that this kind of thing could block his reasoning.

"Then, Zenitsu-kun, I'm fine! You don't really need to do this as a thank you!" Tanjirou's head is spinning. He smells so good. I want to eat him up. "And drop the dono!"

"No?" Zenitsu intentionally makes his kimono slip, "You won't even take a taste?"

Tanjirou tries to look at anything other than the seductive creature in front of him but still his eyes end up on Zenitsu's red lips. They look so soft. He gulps at the swipe of Zenitsu's tongue.

He puts his hands around the alpha's neck and whispers in his ear, "Please? Tan~ji~rou~"


Tanjirou Kamado, barely legal, has an omega with the most alluring scent on top of him kissing him till they lose their breaths, what luck he has!

It's a messy and inexperienced kiss. Their lips touch and their teeth clash against one another. It looks as soft as it feels. Tanjirou's pulse hastens and it feels like his heart is about to burst.

From their closeness he sees Zenitsu has long thick eyelashes that's slightly wet from crying. It makes Tanjirou want to dry it away and never have Zenitsu cry in any way.

And then there's tounge. It's soft and slippery that suddenly darts forward and tries to enter his mouth. It takes him by surprise. He gasps a bit. Zenitsu takes it as a chance to enter his tongue in.

At first Tanjirou has no idea what he's doing. His hands are chaffing from putting his weight on it for too long so he wraps it around Zenitsu's small waist. His tongue is being probed by another; he can taste peaches from Zenitsu and it just feels too good half of his senses are overwhelmed.

He wants to make Zenitsu his. He can smell arousal from him as Zenitsu rubs his body all over. It goes straight to his dick.


He snaps at himself. No matter how much the boy wants this, there was no way he was doing it with someone he barely knew! The person might regret it when they realize they aren't compatible personality wise. Aside from that, he wants to treasure Zenitsu if they were to enter a relationship before moving on to this stage!

Zenitsu breaks away from the kiss and heads on to Tanjirou's neck, specifically, where his scent glands are located and nibbles on it.

So cute! He's so cute!

But they can't do this! He won't do it before they get to know each other.

"Zenitsu-kun! Let me court you first!" He pushes the boy away and finds that he's... sleeping?

Tanjirou is alone in the room with a ravishing and dolled up omega (albeit sleeping). He feels hot and bothered with his dick standing proudly. The owner? Not so much.


"Nii-chan, is that a hickey on your neck?"

"N-no!" He's quick to deny. He hopes that after all these years his face doesn't twist in a weird expression.

"I see..." Nezuko pats his shoulder, "You've grown into a fine man, Nii-chan."

Tanjirou's never been this embarrassed his whole life.