Summary: This is their mania –their obsession, their enthusiasm, their craving. Nothing and no one can stop them, not even themselves. Not that they really want to stop, that is. Warnings: Kageyama/Hinata, kink, masturbation.

AN: So no one said in the reviews they wanted this… but no one in the reviews said they didn't want it. Interpret the lemon below as you will –I kept it vague for that reason. Panther, panther-boy, or some weird-ass role-play –I hope you readers enjoy!

Disclaimer: I do not own Haikyuu. I'm still fairly inexperienced when it comes to dealing with Haikyuu.

"Mania"

Defined as "an excessive enthusiasm or desire; an obsession", synonyms for include: "obsession, compulsion, fixation, fetish, fascination, preoccupation, infatuation, passion, enthusiasm, desire, urge, and craving."

Fetish

Narrator: We start our story long ago. Hinata, a young exotic veterinarian in training is interning at the local zoo. One day a new animal for a developing exhibit arrives: Kageyama –a fully grown black panther! All is well as Hinata gets used to settling Kageyama into his routine while the exhibit is being finished but –suddenly –trouble strikes! Kageyama has entered his rut –and the female black panther has not yet arrived at the zoo!

Narrator: "Oh, no!" Hinata bemoans wondering what to do. In a hope to help his knew friend before getting help from the senior staff Hinata opens the door to the enclosed space and tries to give the panther a dose of sedative strong enough to put him to sleep. Only…

Narrator: Warning! This is if you missed the AN note above –while written vaguely for readers pleasure you can consider this a role-play, Hinata getting nailed by a panther-boy, or him developing a panther-fetish –it does suggest having intercourse with an animal. You have been forewarn.

…to end up on the concrete floor of the underground enclosure with paws much larger and sharper than his own hands holding him still. Closing his eyes Hinata thinks for a moment it is the end –only for a hot breath to be rolled onto his face before a long, sand-paper, tongue to lick across his lips, nose, and forehead.

Blinking his eyes open, Hinata barely gets a breath in before the paws, with long claws extended, rip his shirt and front of his pants to shreds. Even so –it gives him just enough seconds to turn over and crawl his way out from under Kageyama. Only to find himself facing a wall with a very horny, and big, panther blocking his exit out.

Oh. And his ass is now facing said panther, Hinata realizes as a tongue licks across the still somewhat handing cloth. With another soft swipe however, Hinata finds himself corned, naked, and somehow highly aroused.

An deeper growl comes from above Hinata. Above? A shiver runs down his spine and as he looks up deep, yellow eyes darkened and full of innate instinct stare back at him. A beast –not even the usual look of pride Hinata is so used to can be found within.

Something hard, long, and wet presses against his back. Something deep and heavy releases itself from the beast causing the young teen to shiver. Something utterly animalistic calls out to Hinata –and he loves it.

Within moments of the call Hinata's little friend goes from flaccid to ready to burst.

Kageyama purrs in response.

'Shit', Hinata thinks drooling just as little as his own body feels like its burning in a pseudo-heat-like state. Kageyama then seems to decide enough is enough and bends down to start licking the side of Hinata's face.

"Ah," Hinata moans softly and unconsciously moves his head toward the tongue, allowing its length to even enter his own mouth, while pushing his as out as he shifts his weight onto his arms leaning against the corner. Eventually Kageyama pulls away and drags a line of drool with him as he does so, not to mention the drool from his own mug that has dripped onto Hinata's bare back leaving a stream of slick to run slowly down towards the crack of his ass.

"Hm," Kageyama only hums slightly before purring as he rubs his nose into running drool and dropping his paws back onto the ground noses his cold, actual, nose into the sight crack between the two round orbs. Finding the scent of arousal Kageyama instinctually licks several times eliciting heavy, and sometimes high pitched, moans from his to-be mate.

And Hinata, without Kageyama completely covering his body anymore can no longer subconsciously argue that he isn't able to get away. And he doesn't, he realizes, he doesn't want to get away. In fact, before he even is aware of his actions, Hinata reaches behind and pulls those round orbs away from one another to reveal a bright pink pucker that is quickly covered with panther drool.

The heat is getting worse and Hinata only wants more. More. More.

Letting go with one hand Hinata uses the slick and his own arousal to push one of his thin fingers just past the tight ring and pulls down. And as small as the opening was –Kageyama was not about to let it go.

"Oh!" Hinata cries in pain as his body is thrown into the wall, hard dick and all, and is kept pressed there flush as the tip, and even more, of Kageyama's tongue begins to enter his tight passage effectively wetting it.

Hinata is so warm at this point he can't even tell how long him and both his throbbing cock and ass spend in the agony. And then it happens: a deep growl calling him back to reality. Turning his flush head over his shoulders he can watch Kageyama back up and show off his hard and prickled length dripping precious cum onto the ground.

For him.

Forgetting all about Kageyama's rut, about the camera system that hasn't been completely set up, about no one that is going to come looking for him for another few hours, about how wrong everyone else will think this is…

Hinata turns, drops to his knees, and crawls toward the dripping cock, even going under Kageyama and welcomes the warm cum and length into his mouth. Closing his eyes around the unique taste, Hinata knows immediately –he's completely ruined for any human man forevermore.

And so he sucks, slurps, and deep throats the length as Kageyama holds completely still purring deep from within.

"Aaah!" Hinata cries out when his concentration is broken at Kageyama driving his canines into his the left cheek of his ass. In surprising pleasure Hinata finds himself releasing onto the concrete floor with his bleeding ass up and the rest of his body resting down. With eyes closed it doesn't even take more than a minute before he's realized Kageyama has walked the distance around him to begin the mount as he feels the thick and wet instrument drive into him.

Panting Hinata finds himself quickly meeting the panther's thrusts despite having just been spent. And it might just be the hormonal high but when Kageyama finally does let loose and the pain of his prickles comes to the forward of his mind as a heavy knot forms Hinata can't help but think as the word turns black around him…

This is the kind of sex he's been looking for all his life.

AN: Mania is a series inspired by Haikyuu including several pairings, inspired by a request from my personal friend for her birthday! None of the stories in Mania have to do with one another and will be uploaded as one-shots. So read in any order you of your choice!

I think the worst part about writing this is that after I completed the forewarn part both of my cats started to bother me… they know! They know!

PS. This is like double the length of most of my other chapters for this story and I just literally completed it –why do all my professors have the same due date for all their work?