Posted originally on the Archive_of_Our_Own at https://archiveofourown.org/
works/7904296.
  Rating:
      Explicit
  Archive Warning:
      Underage
  Category:
      M/M
  Fandom:
      Haikyuu!!
  Relationship:
      Kageyama_Tobio/Ushijima_Wakatoshi
  Character:
      Kageyama_Tobio, Ushijima_Wakatoshi, Hinata_Shouyou, Ennoshita_Chikara,
      Takeda_Ittetsu, Ukai_Keishin
  Additional Tags:
      Mating, Mating_Rituals, Mating_Bond, Mating_Bites, Knotting, Fluff_and
      Smut
  Series:
      Part 9 of Mating_Night, Part 17 of Crack_ships_and_rare_ships
  Stats:
      Published: 2016-08-29 Words: 2315
****** Kageyama & Ushijima ******
by Bittodeath
Summary
     There is an old tradition in the lost villages of Haikyuu, to make
     sure there are no unmated young people: once every three years, at
     night, all the youth between sixteen and eighteen are gathered at the
     entry of the village, Omegas and Alphas alike. They presented as
     either Alpha or Omega and, under the watch of the leaders of the
     village, Omegas are sent into the forest, to run and hide themselves.
     A moment later, Alphas are sent after them. The first Omega an Alpha
     manages to grab is destined to become his mate, and they have to mark
     each other during the night and come back to the village once mated.
Notes
     This. Was. One of the hardest pairings. With Kyoutani and Kenma.
     But it was funny and writing Ushijima like that was... an experience.
See the end of the work for more notes
There is an old tradition in the lost villages of Haikyuu, to make sure there
are no unmated young people: once every three years, at night, all the youth
between sixteen and eighteen are gathered at the entry of the village, Omegas
and Alphas alike. They presented as either Alpha or Omega and, under the watch
of the leaders of the village, Omegas are sent into the forest, to run and hide
themselves. A moment later, Alphas are sent after them. The first Omega an
Alpha manages to grab is destined to become his mate, and they have to mark
each other during the night and come back to the village once mated.
This technique is not perfect, but everyone is mated and since their other
senses are hindered, most Alphas rely on their sense of smell and end up
choosing the “best smelling” partner, who is biologically the most compatible.
Thus, blood lines are strong – and no one can complain that they were chosen or
rejected. “Mating Nights” are joyous occasions, often followed by a consequent
number of births.
 
Karasuno Village is a particularly remoted village, with only two women but
luckily just an even number of young Alphas and Omegas. And the “mating night”
as finally arrived, under the supervision of their leaders, Ukai and Takeda –
or, as they are called now that they are mated, Keishin and Ittetsu. They have
gathered all their young ones, eager, bored, excited or frightened.
“It is night. You may go.”
 
Kageyama fidgeted. He knew he was too Alpha to make Omegas comfortable around
him, and even Alphas were wary of his angry face. Not like his resting-bitch
expression was something he could change. But tonight, it was Mating Night and
it meant he was supposed to find his mate. His Omega. If he wasn’t nervous
about the practical details – no, he hadn’t discussed it thoroughly with other
Alphas. Nope. – he sure was when he thought about the long-term relationship it
meant. He didn’t want his Omega to be unhappy. He didn’t even know what kind of
Omega he would like. Sure, he was very Alpha-like in his behaviour, but he had
never had the small click that made him say “this one is the one”. Too
submissive. Too small. Too sweet. Too pushy. Too competitive. There was always
something that drove him away.
Then again, maybe he was just being difficult, but when he observed Keishin and
Ittetsu, he couldn’t help but want a similar relationship, made of a deep
respect and profound love. Of course it would take time. But if his mate was
afraid of him, or hated him, things would be a lot harder. He sighed, observing
his fellow Alpha companions. Well, at least he wasn’t the only one nervous.
Bokuto seemed to be about to break a fuse, and God he had never seen Daichi
like this. Even Hinata was bouncing everywhere.
Keishin was discussing something with his mate, frowning. Slowly, he stepped
closer. Eavesdropping was bad but sometimes it was really useful.
“Are you sure we made the right decision when we sent him with the Omegas? He
doesn’t look very Omega-like and he should have presented long ago. He is one
of the oldest for this Mating Night”, Keishin said.
“He said it was alright”, Takeda answered. “And it would be a problem if we had
an uneven number of Alphas and Omegas. Even if he doesn’t bond with the Alpha
who will found him, they’ll both have someone to spend the night with. It would
be very frightening otherwise. Besides-”
An Alpha suddenly ran out of the forest where he had been helping getting the
nest ready – he was nicknamed the Little Giant, and though he was small,
everyone respected him deeply. Everyone except his Omega – but Saeko wasn’t an
average Omega, after all. He stopped next to the leaders, panting.
“He presented!” he said in a relieved tone. “I went to see how he was doing and
it seems the stress pushed his presentation.”
“And?” Keishin asked in a steely voice.
“Omega!” the Little Giant said with a bright smile. “He presented as an Omega.”
Relief washed over their leader’s features.
“That’s good”, Keishin muttered, “that’s very good. We can start.”
Kageyama scurried away as Keishin looked around and yelled:
“It is night! You may go.”
 
He ran off like the others, but he was now preoccupied with a question: who was
the newly presented Omega? He ran, unaware of the multiple scents around him.
He ran for a long time, trying to remember everything he knew about the people
participating in this mating night. Hell, he wasn’t any good at remembering
things like that. He wasn’t- He was on the floor, growling in pain as he put a
hand over his nose. Shit, something was dripping – like he needed a bloody nose
right now. Well maybe he should have paid attention and not run into a tree,
but still.
“Are you alright?” a voice said somewhere near him.
“Yeah”, he answered, pushing himself up.
Finding an Omega when he could only rely on his smell and now had a bleeding
nose was the easiest thing in his life. Goddammit. As if he needed that. He
looked up, feeling a strong presence beside him. Surely enough, someone big and
bulky was hovering over him.
“You smell really good”, they said, leaning forward.
A ray of moonlight illuminated the scene and he gasped.
“Ushijima?!”
It was indeed Ushijima, with his stern face and expressionless eyes. Wait a
minute. Those eyes weren’t exactly expressionless. Kageyama peered into them,
startled when he lost sight of them as Ushijima buried his head in his neck,
taking in his scent and nuzzling his gland. The young Alpha stilled, a hand
still trying to stop the bleeding.
“I love your scent”, Ushijima said, and finally Kageyama’s nose stopped
bleeding – it was too late to save his shirt but well – and he caught in an
enticing scent. It was still rather faint, but it smelled good. A bit spicy
with a note of citrus. Instinctively, his hand shot up to Ushijima’s neck,
gently rubbing on his gland. The scent grew stronger and Kageyama gasped.
“You’re an Omega!” he exclaimed, and Ushijima nodded.
“I just presented a few hours ago and I’m as surprised as you are”, he simply
said, and he didn’t look nervous or anything. Perhaps just… relieved.
“So it’s you they were talking about”, Kageyama muttered. Then a thought hit
him like a train. “Wait a minute. Does this mean I am your Alpha?”
Ushijima cocked his head.
“Well I guess it does, yes.”
It took everything Kageyama had not to collapse on the spot. His Omega.
Ushijima Wakatoshi was his Omega. He had never imagined such a scenario. He
brought his hands to his head.
“We… Need to talk”, he finally said.
“Let’s go to a nest, then”, Ushijima said, waiting.
Kageyama stared at him for a few seconds before leading the way to the nearest
nest. They were cocoon-like things made of branches and filled with wool,
feathers and leaves, blankets folded inside. Designed for Omegas to feel safe
while mating. They climbed in, the construction creaking slightly under their
weight. There was an awkward silence as Kageyama thought everything over.
“If you hadn’t presented until now”, he finally said slowly, “no one explained
you anything about Omegas?”
Ushijima nodded. They were only given explanations concerning their gender once
they had presented, which meant the Omega didn’t know a single thing about
mating cycles. Hopefully enough he would know how to ma- Wait no. He wouldn’t
know. No one would have told him without knowing his presentation, and he
hadn’t had any sexual urge until now. Kageyama groaned. He wasn’t the most
patient person ever and this was getting ridiculously complicated. And he
didn’t have enough time to explain his mate-to-be how his body worked, since he
had already spent a good part of the night running.
“I’ll… I’ll explain everything to you later, okay?” he finally said, his voice
strained. “For now we have to mate. Trust me, okay? Trust me and trust your
instinct.”
Ushijima nodded, staring at him intently. He wasn’t really making things
easier, but Kageyama came closer, taking his face between his palms.
“It’s going to be alright”, he murmured soothingly, and the stiff Omega relaxed
against him.
Gently, Kageyama leaned closer and kissed his lips. It was clumsy at first, but
soon enough they grew confident and he let his hands roam over the Omega’s
body, feeling it shiver under his touch. Ushijima’s large hands settled on his
back and it felt good – it felt like home. He started to undress the both of
them, Ushijima leaning closer to smell him, the strong Alpha scent probably
making him dizzy. He had never gone into a heat, then. Kageyama frowned. He
hoped everything would be alright. He slid lower, lips stimulating his Omega’s
chest who gave him a full body shudder, while his hands slid down to Ushijima’s
crotch.
“I feel really strange”, Ushijima murmured.
“Are you uncomfortable?” Kageyama asked, concerned.
“No, just… I feel warm.”
Kageyama sighed in relief. For a moment, he had feared he had done something
wrong. Slowly, he pumped his mate’s shaft in his hand, watching attentively as
Ushijima threw back his head with moan. His second hand went down, brushing
against his thighs and- His heart thumped when he felt the warm slick against
his fingers. At least he was aroused. Softly, he pushed a finger in, feeling
the Omega clamp down on him.
“Are you okay?”
Ushijima nodded weekly, and Kageyama pushed his finger deeper, searching for
that one magical spot that would sent his mate to heaven. He knew he had found
it when Ushijima moaned rather loudly, back arching, and Kageyama coaxed him
into laying down, pressing a second finger to his entrance. He took his time
preparing Ushijima, spreading his fingers and thrusting slowly, brushing his
prostate every now and then to watch him close his eyes as he lost himself to
the pleasure. He pulled back and slicked his painfully hard cock; he wouldn’t
take long in forming a knot.
“I’m going now”, he murmured against Ushijima’s lips, pushing in carefully.
His Omega yielded under the pressure, presenting his throat and relaxing under
his touch. He reacted so beautifully, Kageyama was entranced. This was what he
had always wanted. An Omega would challenge him and still trust him to take the
lead, an Omega who was a partner but always came back to him when they needed
to be comforted. He had not doubt now. Ushijima was the one. He grunted as he
bottomed out, going as slowly as he could.
“Is it okay? I’m going to move know”, he said, and Ushijima nodded, not even
trying to use his voice.
His thrusts were gentle at first, when he was still capable of holding himself
back. But it felt so good, better even than everything he had heard – and he
lost it, snapping his hips forcefully against Ushijima and making him cry out,
his eyes drowned in pleasure as he coaxed him higher, higher, higher – until
Ushijima fell over the edge with a gasp that sounded like his name. Kageyama
managed to give a few more thrusts before his knot fully swelled, trapping him
inside as he came. Ushijima reacted first, his teeth sinking down into his
throat, over his gland, marking him. Kageyama mimicked his action, biting until
he drew blood – claiming his Omega.
Ushijima moved, trying to pull away, and whined when the knot caught, prevent
him to move. Kageyama immediately pulled him closer.
“You can’t move yet”, he said. “My knot is inside of you, we have to wait until
it deflates”, he said. “You feel it?” he asked, his palm gently pressing
against his lower stomach, and the Omega gasped.
“I do.” There was a silence, and: “I’m glad to be an Omega, and I’m glad to
have you as my Alpha.”
Kageyama didn’t answer, feeling he hadn’t said everything.
“To be honest, I was afraid of presenting as an Alpha. I didn’t want to be in
charge everywhere, it would be too much. I wanted… someone to take care of me.
That’s probably why my presentation was delayed that much.”
Kageyama hugged him tightly.
“I’m here now”, he said. “I’m going to protect you. You just have to trust me.”
Ushijima nodded, pressing his face in the crook of his neck once more. Finally,
Kageyama pulled out and settled against him, fingers drawing idle patterns over
his chest. Sure, Ushijima didn’t look like an Omega. But he was – and he was
his. He opened his mouth, and started to explain everything he could. About
mating, about the bond, about his heats. About how babies were made. This last
part made the Omega frown, when he had simply been enchanted by the idea of a
heat – by the idea of craving his Alpha and having him for himself, by the idea
of the pleasure waiting for him round the corner. He looked down his body.
“Me? Carrying a baby?” he said. “This sounds ridiculous.”
“One day”, Kageyama murmured against his lips as he kissed him, a palm pressed
above his crotch. “But not now.”
They finally drifted to sleep, the covers hanging over their entwined legs.
 
“We should wake them up”, a voice murmured – Hinata’s.
“If Ushijima presented last night, he might be exhausted”, Ennoshita answered.
“And they look cute together, sleeping like that.”
Kageyama opened one eye and stared at them.
“If you wake him up I swear I’ll break your bones”, he hissed. “All of you.”
He pulled his sleeping mate closer, nuzzling him softly. Nature knew what she
did when she made Ushijima an Omega. She knew he would be what he needed.
Kageyama smiled softly.
“Thank you.”
End Notes
     I hope you liked it, as usual don't hesitate to comment either here
     or on my tumblr, bittodeath.tumblr.com!
     Three more pairings to go, and the last part where we'll get to see
     all of them a while later. Because we all need fluff.
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