Alright, so this is the very first story I've ever written. I'm going to try to make it a long one (for a fanfiction), so it will have at least ten chapters. It will have mpreg and mating season and heat and all that. The pairings are pretty obvious. So, read it and tell me what you think! :)

DISCLAIMER: I do not own Yu Yu Hakusho or any of its characters. This story if purely fictional and made up by me. The actual Yu Yu Hakusho characters are not gay and can't get preggers. But, while I'm on the subject, wouldn't it be awesome if they made a yaoi version of Yu Yu Hakusho?

It was hot. Horrifically, horribly, unbearably hot. Not because of the weather, since it was springtime and a beautiful drizzle of rain was falling outside, making it cool at the most. No, it was hot because mating season had decided to rear its ugly head, and now all the demons in the worlds were, have, or would be going through heat, and consequently feeling the overbearing, irrepressible, hot need to mate, or at the very least have a good roll in the hay.

All demons had to go through heat. For some, it happened once or twice in their lives. Others, it happened every year. But, for some odd, probably-can-be-explained-by-a-long-scientific-explanation reason, heat in every demon always occurred through the winter and spring months, with heavy emphasis on the spring months. This made many demons happy and many other demons sad. For many demons, it became "Sex Time" and they would intentionally go out to have as much sex as possible before the season was over. For all the other demons, it became time to go find a nice, secluded place, put up as many wards as possible, and wait it out, which was never fun.

Hiei would know.

Hiei was unfortunate enough to take after his father's side of the family. Fire demons were notoriously horny creatures, renown for their sexual prowess and for going into yearly heats. Which was a good thing, if you thought about it. Yearly heats meant LOTS of reproduction, and since fire demons were such hotheaded, bloodthirsty creatures that were constantly getting into fights and getting killed, they needed all the reproduction that they could get. But at that moment, Hiei couldn't have cared less about the varying populating count of fire demons, as he was too busy cursing them in every possible way.

Heat was never a fun experience, especially waited out. Pretty soon, Hiei would be feeling as if he was on fire, burning from the inside out. Irrepressible need would coursed through him, distorting his thinking to the point that all he could think about or focus on was wanting to be screwed until he passed out from exhaustion. He needed him, not someone, him. The man he had developed feelings for despite every part of him telling him no. There was no other person Hiei would rather mate with, be bound together with for all eternity, have children with. But foxes were fickle creatures, well-known for exploiting mating season as "Sex Time" and leaving a mile-long path of broken hearts and illegitimate babies in their wake. The idea that Kurama would want to settle down with him, the Forbidden Child, was laughable.

And so rather than confront Kurama about mating, Hiei instead left the Demon World to lodge at Genkai's house with his sister and Genkai, believing that he would be safe from the hoards of horny demons that would be roaming Makai.

Oh, how wrong he was.

Hiei did not find out about how wrong he was until it was too late and he was already comfortably lodged in room in Genkai's manor, his heat starting. He was beginning to feel uncomfortably hot and his thoughts kept drifting away to a certain fox, becoming increasingly naughty as time passed, and making it incredibly difficult to maintain a conversation with his twin.

True to his word, Hiei had never told Yukina that he was her brother, but he never denied it either. From the first moment she saw him, Yukina had suspected that Hiei was the long-lost brother she was searching for, and his actions only confirmed her accusations. When she confronted him about it, she took his shocked silence as a "yes" and promptly glomped him.

Luckily for them, heat didn't affect family members, and so Yukina could converse with her brother without being affected by the pheromones he was giving off.

The two were currently sitting in Hiei's guest room, with Hiei sitting on a futon, fanning himself with an uchiwa, and Yukina kneeling beside his bed, using her power to make the temperature of the room 32 degrees F.

"You should tell him," she said in her gentle voice, handing her brother a bowl of chocolate ice cream mixed with brownies. Hopefully, the cold ice cream would cool him down a little.

"No." Hiei took the ice cream and began to scarf it down as fast as he could without getting a brain freeze.

"He feels the same way! I can tell," Yukina insisted.

"How can you tell?" Hiei question, licking the bowl and trying to prevent himself from thinking about what he would rather be licking.

"Women's intuition," Yukina answered simply, handing her twin an ice cream sandwich. Ice cream was her brother's favorite treat and Yukina had taken the liberty of stocking up on ice cream just for her brother's convenience. Currently, she was sitting by a huge mountain of different sorts of ice cream.

Hiei snorted loudly and derisively.

Yukina resisted the very strong urge to chuck one of the large tubs of ice cream at her brother's head. "You can't be that blind! Haven't you noticed all the hints he's been giving you?"

"What hints?" Hiei bit into his ice cream sandwich as he pondered over his past history with Kurama. Everything seemed normal to him. "Name one."

Yukina rolled her eyes. Really. And she was the naïve twin.

"Haven't you ever noticed all the looks he gives you? Only you? Or all those ridiculously obvious passes he makes at you?"

Hiei gave her an annoyed, what-are-you-talking-about look over the carton of ice cream he had just dug into.

Yukina was suddenly overcome with wanting to beat her brother's head into the wall.

"He's always winking at you."

"His hair probably gets into his eye. It's really long."

"Kazuma-kun told me that whenever you four are on a mission and have to stay at a hotel or camp out, Kurama-san always insists on sharing a tent, a room, or a bed with you!"

"I wouldn't want to sleep next to that big oaf, either."

"He says these really sexual comments to you all the time – and don't call Kazuma-kun an oaf!"

"You're not even supposed to know what sexual is! And give me an example."

"I'm the same age as you! And, let me pick out a good one… oh, I know, the one he used two weeks ago: 'Hey, Hiei, if I flip a coin, what do you reckon my chances are of getting head?'"

"You're an ice apparition! And my sister! You're not supposed to know those things! And I told Kurama that he has a fifty percent chance of getting heads."

"You're hopeless."

"You're delusional."

The twins stopped their arguing to glare at each other in frustration. Hiei was the first to look away. He could never glare at Yukina. It made his eyes twitch, which would make her laugh. Instead, he reached over to grab another ice cream bar.

Yukina sighed heavily and began to ponder about the likelihood of her ever becoming an aunt. She looked up and out the bedroom window, lost in thought. It just then struck her that she had things to do.

"Oh!" Yukina exclaimed, jumping to her feet. "I just remembered! I have things to do."

Hiei, now lying on his side with his head supported by his hand, glared up at her. "I thought you said you had all your chores done."

"I meant household chores. I promised Genkai that I'd help prepare the rooms for the guests." Yukina began to gather up all the wrappers and Popsicle sticks that were scattered about on the floor.

Hiei then inhaled a bit of hard chocolate from his ice cream bar and began choking. "W-what?"

"Did you think that you were the only demon that thought of taking refuge here during mating season? Of course not! Yusuke-san, Kurama-san, Jin-san, Touya-san, Suzaku-san, and Shishiwakamaru-san are also taking refuge here."

Hiei wanted to kill himself. Everyone he knew and hated was coming here to find some solace in the heated frenzy of the season, and they would know he was here as well and hear him. In his past two heats, Hiei had learned that he was anything but quiet. He began to wonder if it was too late to escape.

But Yukina's twin-sense had kicked in and she guessed at Hiei's thoughts. "Don't even think about leaving – lots of demons will be prowling around, even here in the Human World. You know that rape accounts go up at this time of year, and if they catch your scent, you'll be completely helpless. At least here you'll be safe. Genkai won't let anything happen to any of you."

Hiei groaned in misery.

"And, besides, Kazuma-kun, Shizuru-san, Botan-san, and Keiko-san said they'd come by to help!" Yukina said cheerfully.

Hiei fell back onto his back and covered his face with his hands. He just knew that this was not going to go well. "More like cause a lot of trouble for their amusement."

"Onii-san! We would never do anything that we didn't think was for the better."

What happened to his sweet, innocent, and naïve little sister? Ever since she had decided to live in the Human World and go on those pointless "Girl's Night Outs" with Botan, Keiko, and Shizuru she had started to become more evil: plotting against him and knowing what "sexual" was.

It was enough to put any older brother into a moody depression.

"That's what worries me," Hiei snapped. He sighed, knowing that he had no choice but to comply and remain in the guest room, placing all his faith in his sister, Genkai, Botan, Shizuru, Keiko, and the Big Oaf to protect his virginity.

He was screwed.

But pretty soon he would be hoping for the girl's meddling. Come midnight, his heat would really begin and his perverted thoughts would transform into dire, desperate need and he would be clawing at the door to get out, find Kurama's room, and get at it like bunnies.

But now he was mostly calm and rational, many visions of Kurama naked and doing naughty things to him flashing through his brain. Yukina had finished picking up the wrapper and Popsicle stick mess and was heading for the door. As she was just about to open it, Hiei called out to her:

"Tell the Big Oaf to remember what I said."

Yukina gave him a curious look. "What did you say?"

"Just tell him to remember what I said."

Never in all his life had Yusuke felt more uncomfortable. Kurama had warned him about heats but he didn't think they'd be this bad. He felt as if he was on fire, his skin hot to the touch and he was covered in one of those post-sex sweats. He desperately wanted to jump every girl and boy that crossed his path, but somehow managed to control himself.

Walking into Genkai's manor, Yusuke was met with six faces all bearing the same mixture of amusement and worry.

"What the hell, Grandma?" Yusuke asked irritably as he gave everyone in the room a harsh look, daring them to comment on his predicament. "I thought you said it would be just you and Yukina."

"No, I said it was just Yukina and me living here," Genkai calmly replied, sipping her cup of tea. She and the others were having tea in her living room before Yusuke arrived, talking over things. "But Yukina felt that we might need more help in the coming week attending to seven demons in heat, and so she called in the squad." Genkai lazily gestures to Kuwabara, Shizuru, Keiko, and Botan.

"I thought it was just going to be me here!" Yusuke hissed at her, seething. Great, he was going through his first heat since becoming a demon and he also got an audience. From how Kurama described heats to be like, an audience was the last thing he wanted. He just wanted to curl up in one of Genkai's expansive, comfortable guestrooms and piteously wait it out.

"You dimwit, you're not the only demon that wanted some solace from the craziness in the Demon World during this time. Two of your former partners and some of my newest disciples have asked to stay here while they're in heat."

"Do you mean Kurama and Hiei?" Yusuke exclaimed.

Genkai nodded. "And Jin and Touya and Shishiwakamaru and Suzuka."

"Terrific," Yusuke muttered angrily. "Just make sure they stay as far away from me as possible." And he stomped off to his guestroom.

"Of course, Yusuke!" Botan called after him. "We wouldn't dream of letting them near you! You're safe with us!"

"Wait, what do you mean by 'heat'?" Kuwabara asked Genkai. "What, is Urameshi sick or something?"

Botan looked at Yukina. "You didn't tell him?"

Yukina shook her head. "Shizuru-san said she would."

Kuwabara turned to glare at his sister. "Gee, thanks a lot, Sis!"

"Sorry, Bro, but I knew that if I told you, you wouldn't of come." Shizuru blew smoke into her brother's face.

"Ack! I hate it when you do that! And what do mean? What's wrong with Urameshi and the others?" Kuwabara demanded.

"Nothing, really. What they're going through is perfectly natural and expected, like puberty," Botan said.

"What do you mean? I'm confused. Are they going through demon puberty?" Kuwabara, the loveable lug that he was, was as slow as ever.

"No, you big dummy. Botan was just using that as an example," Shizuru said. "Genkai, Botan, why don't you both explain what heat is? As slow and simple as you can so even dufus over hear can get it."

"Shut up, Sis!" Kuwabara snapped.

"Quiet, both of you," Genkai snapped. "I will not have you bickering like children all week. It's going to be busy enough here without you two fighting."

Conciliated, Kuwabara and Shizuru fell silent.

Pleased, Genkai turned to Botan. "Now, Botan, I'm sure you are much more familiar with demon mating seasons than the rest of us are. Why don't you tell us what you know?"

"I'd be glad, too, Genkai!" Botan said cheerfully, happy to be of use. She was used to explaining things, anyway. "I'm going to try to explain this as simple and best as I can, as it can get a little bit complicated. You see, all demons go through what is called "heat" at least once in their lives. "Heat" is basically a condition that they go through when they are entirely consumed with the urge to have, err, intercourse and mate with another demon. While a demon is in heat, a number of things happen: they get very, very hot with, well, need, making them go almost absolutely crazy until they have s-sex with another demon, preferably one of their choosing. This specially designed heat does another thing, however: it causes most demons to excrete a pheromone through their skin, which causes them to be more desirable to other demons, thus increasing the chances of having sex. Besides the need and the pheromones, they become much more temperamental and tend to consume high levels of sugar…."

"It doesn't sound that bad," Kuwabara interrupted. "Sounds like an excuse to get laid for a week, to me!"

"Well, most demons take it like that," Botan continued. "Mating season had the nickname 'Sex Season' for a reason, you know. Go to Demon World now and you're bound to get caught up in an orgy or be raped."

Kuwabara winced. "No kidding?"

Botan shook her head. "But that's not the worst of it. You see, demons will become so consumed with need while they're in heat that they will lose all control and have sex with anything in sight. Can you imagine? Remember that annoying girl Koto from the Dark Tournament? She ended up being knocked up by some big, ugly demon twice her size and covered in warts."

The others shook their heads in pity for the girl. Yeah, she was sadistic, catty, and annoying, but no one deserved that.

"But besides the need and the rape is something else just as threatening," Genkai said ominously, taking over the explanation.

"What?" Keiko asked.

"While a demon is in heat, its fertility levels sky rocket, making it much easier for them to reproduce. Now, a demon can reproduce at any time, but heat makes it much more easy to get pregnant, especially for many species of demon." Genkai took another sip of her tea.

"Explain," Shizuru said curiously.

"Most of you may not know this, but there is no definite line between male and female demons. In truth, they're really neither, despite how they look. Both 'male' and 'female' demons can reproduce. The real big difference is that female demons – " Genkai looked pointedly at Yukina " – can reproduce asexually while male demons cannot, and female demons have a much easier time getting pregnant when they're not in heat. That and they can birth the babies naturally and breastfeed them. For male demons, the babies have to be cut from the 'mother' and have to be given nutrients from something or someone else, like a surrogate mother. "

Kuwabara looked green. "S-so you're telling me that Hiei and Kurama and now Urameshi can get pregnant?" He looked as if he would vomit, more than likely from imagining his three friends and comrades giving birth. "But that's so – so weird."

"To us, yes, but in the Demon World it's a very natural occurrence," Genkai said nonchalantly.

Unlike Kuwabara, the girls were giggling over the new information.

"Can you imagine Hiei preggo? He'd be so cute!" Yukina giggled.

"I can't imagine Yusuke pregnant!" Keiko laughed. "I mean, I know he's Bi, but I can't imagine him allowing anyone to dominate him and get him knocked up!"

"Kurama would make a wonderful mother," Botan hooted.

And they fell on the floor; laughing themselves silly as they pictured all the big scary demons they had met with baby bellies. A sharp "Ahem" at the door interrupted their laugh session.

"Oh, Kurama, we didn't see you there!" Botan exclaimed, wiping a tear from her eye.

Standing in the doorway was Kurama, looking hot and bothered but considerably more in control and composed than he should've been. He gave the girls one of kind, gentle smiles and said, "Good evening. I trust that you are all well?"

"Of course! Genkai and I had just finished explaining to the others what heat was," Botan said in her usual cheerful manner.

"I take it that I'm the last to arrive," Kurama said, addressing Genkai.

A small smile appeared on her face. "So you knew?"

"I expected as much. Who else is here besides Yusuke and Hiei?" The others did not miss the look that came into Kurama's eyes when he said Hiei's name.

"Some of my past students: Jin, Touya, Shishiwakamaru, and Suzuka. They arrived earlier today. Hiei's been here since yesterday and Yusuke came about a half hour ago. They haven't left their rooms since they arrived here. I believe they put up wards on their doors, though not very good ones."

"Understood. I should do the same." Kurama turned to them all and bowed politely. "I bid you all good night." With that, he left in search of his room.

"What are the wards for? To keep others out or them in?" Shizuru asked Genkai after Kurama left.

The old woman smiled mischievously. "Neither. I gave them those wards. They're located in all the guest rooms for the guests to put up. They're specially designed for demons in heat. Normally, a demon's pheromones leak all over the place when a demon's in heat, spreading out for miles even. But these wards are especially made to contain a demon's pheromones."

"That's great!" Keiko exclaimed. "But it kind of goes against the plan."

"What plan?" Kuwabara asked, but was ignored.

"I wasn't finished," Genkai said. "The wards have another feature. They can tap into a demon's desires and see who the demons wants the most, and then they focus all the pheromones on that demon, no other."

"What are you girls planning?" Kuwabara asked nervously.

They ignored him.

"That's brilliant!" Botan exclaimed. "You're brilliant, Genkai! Now they can't help but mate!"

"I'm so confused. I thought they came here to not mate," Kuwabara interjected.

"Little brother, you are so slow," Shizuru said impatiently. "Of course that's what they came here for!"

"Then why are you trying to get them to mate?" Kuwabara asked.

"Because they want to!" Shizuru snapped impatiently.

"But you just said that they didn't want to!" Kuwabara exclaimed, completely confused

"Men!" Shizuru shook her head in mock misery. "They don't understand anything."

"Honestly, Kuwabara, how long have you known them?" Keiko asked him dubiously.

"You cannot be that slow," Botan said skeptically.

"I'm not slow! I just have no idea what you're talking about!" Kuwabara shouted.

Keiko shushed him. "Be quiet! You could make them come out here and overhear our plan."

"I pretty sure they're not leaving their rooms," Botan said. "By now they're probably wallowing in lonely misery – but not for long!"

And all the girls, including Genkai, laughed. Meanwhile, Kuwabara was looking like a kicked puppy.

"Would someone PLEASE explain what's going on!" he begged.

"I'll tell you, Kazuma-kun," Yukina said in her sweet, gentle voice.

"Thank you, Yukina-chan!" Kuwabara said, looking incredibly happy.

"You see, Hiei loves Kurama-san and Kurama-san loves Hiei, but Onii-san's doesn't believe Kurama-san loves him and Kurama-san is not being forward enough with his feelings. And it's almost the same with the others – Jin-san and Touya-san, Suzuka-san and Shishiwakamaru-san. They all have feelings for each other, but are completely unaware of the other's feelings. Which is why it's so fortunate that they all asked Genkai-san if they could stay here, as now we can bring them together and put an end to their misery."

Kuwabara looked completely and utterly shocked. Now that he thought about it… How could he be so stupid? It was so obvious! How protective they were of one another, how strangely jealous they got, how they always seemed to be glued to their counterpart's side.

"But, what if one they get p-pregnant?" Kuwabara asked.

"If Hiei, Touya, and Shishiwakamaru are smart and take the medication I left out for them, we won't have to worry about that," Genkai cut in.

"You left them medication? What kind of medication? And how do you know that Hiei, Touya, and Sissy-Wakamaru are the ones that'll get knocked up?" Kuwabara asked.

"I left them some birth control designed for male demons. And it's obvious who would end up on bottom, and not just from their actions. I forgot to mention that some male demons are more fertile than others, and consequently more submissive during mating season," Genkai explained.

"So basically," Kuwabara said, trying to sum it all up. "They all asked to come here, and you five saw the opportunity to play matchmaker and essentially have them hook up."

"Oh, not just hook up," Botan said. "Mate."

"And how is 'mating' different from hooking up," Kuwabara asked.

"Mating is like marriage," Botan explained. "But much, much, much deeper. It's very serious, like true love. When two demons mate, their souls and destinies are intertwined. They can't live without one another." Botan sighed dreamily. "It's so romantic."

The girls nodded. Even Genkai had a dreamy look flash through her eyes briefly.

Kuwabara thought, And I thought marriage was bad!

Then something occurred to Kuwabara that hadn't before. "Wait a minute! Kurama and Hiei, Jin and Touya, Suzuka and Shishiwakamaru – what about Urameshi?"

"That one's still a work in progress," Botan admitted. "We're still trying to work out the kinks."

Kuwabara turned to Keiko. "It's not you, is it?"

"No, Yusuke and I fell out of love a while ago. We both realized that the love we felt for one another was brief, and that the love we will always feel for one another is not of the romantic sort. Yusuke will always be in my heart, and I will always be in his, but not as a lover." Keiko said.

"Then who – you guys aren't planning on making Urameshi mate with some random demon, are you?" Kuwabara looked outraged.

"What do you take us for, lil Bro? We would never do that!" Shizuru snapped.

"We know of someone – you obviously don't but we do – but getting them together forever is extremely, extremely complicated," Botan said.

"Am I allowed to know who it is?" Kuwabara asked.

"If you can't figure it out for yourself, than no," Keiko replied.

"Sleep on it, Bro," Shizuru said with a yawn. "Maybe even you could figure it out."

With that, the six of them bid each other good night and went to bed.

They were the only people in the mansion that got any sleep that night.

So, how'd I do? I already have the second written so I'll be posting that VERY soon. Reviews are constructive criticism are appreciated! No flames, please, let's all try to get along and be nice to each other.