Title: Forbidden

Summary: When Yami accidentally discovers where Kaiba works, it takes their rivalry and relationship to a new level. AU fic.

Pairing: Yami x Kaiba, Kaiba x Yami

Rating: M for graphic lemons, sexual content, and mature language.

Disclaimer: Yu-Gi-Oh! does not and never has belonged to me.

A/N: There will be lemons aplenty in this fic, so you have been forewarned. In an unusual turn of events for me, it will primarily be Yami x Kaiba, although not exclusively. So for those who like Kaiba x Yami, don't lose hope, there's stuff in here for you, too.

Also, please note that this is an AU fic and there will be a lot of differences. Yami isn't from the Millennium Puzzle, there is no ancient Egypt connection, Gozaburo is still kicking around, and Duel Monsters and the Kaiba Corporation isn't quite what it used to be…

Chapter 01: The Best Laid Plans

"Man, tonight is going to be awesome!" Jounouchi exclaimed to his friends as they waited for homeroom to start. "Yuugi, are you sure you can't join us?"

Anzu scowled disapprovingly at Jounouchi in a semi-joking manner that made Yuugi blush a little at his girlfriend's reaction. "We'll still be there for your birthday dinner, Jounouchi-kun," Yuugi reassured his friend.

"Yeah, but later is when the real fun begins," Jounouchi protested, unable to stop the perverse grin from appearing on his face. "Yami, you're still in, right? Since Honda apparently pussed out on me, too."

"Hey, it's not my fault my sister's babysitter canceled!" Honda defended himself, less than thrilled that he has been called out on a favor on such an important night.

Bracing himself on his hands as he reclined against his desk, Yami sounded amused as he confirmed, "Against my better judgment, yes."

Laughing loudly at his friend's answer, Jounouchi joked, "At least one of you manned up!"

"He's probably only going to make sure you don't do anything stupid," Anzu pointed out, causing Jounouchi to growl good-naturedly. "Besides, I fail to see how any of this 'makes you a man,' as you put it."

"Pfft, you just don't get it because you're a girl," Jounouchi said dismissively, earning him a huffy noise of indignation from Anzu.

"Jounouchi-kun," Yuugi said in a mildly reprimanding tone, even though he knew saying anything would be useless.

As Anzu started to defend herself in a flurry of annoyance, Jounouchi was distracted by a snort from the back of the classroom that instantly had him on edge. "And what the hell do you have to say about it, bastard?" Jounouchi loudly demanded, glaring at the source.

Kaiba merely arched an eyebrow as he lowered his book, his cold eyes regarding Jounouchi with disgust. "I almost find it amusing that you believe your plans will somehow change you from a mutt to a man," Kaiba insulted, smirking arrogantly when Honda had to hold Jounouchi back from an attempted assault.

Jounouchi's blood boiled with rage; he hated Kaiba Seto more than he was even capable of understanding. Kaiba's haughty attitude and demeanor never failed to piss Jounouchi off and he wanted to beat that smug bastard into a pulp more than anyone else in their school.

Blatantly ignoring Jounouchi's fevered ranting, Kaiba's gaze drifted over to Yami, subtly tracing up his lithe form until their eyes met. Icy glaciers were melted by crimson brightness into freezing blue flames and Kaiba's expression mirrored the shift of his interests. Ever since Yami had transferred to the school almost two years ago, he and Kaiba had a long-standing rivalry that spanned from academic efforts to sports and everything in between; it was always intense and exhilarating, even if the battles were pointless posturing at times.

"I guess I shouldn't be surprised that you'll be going along to hold his leash," Kaiba sneered, chuckling when Jounouchi's indignation hit a new volume.

"Nor should I be surprised that you've taken an interest," Yami smoothly countered as he tilted his head to look back to get a better glimpse at Kaiba, a knowing look in his eyes.

Piggybacking on Yami's comment, Jounouchi all but shouted, "Yeah, what the fuck is your problem, asshole? Always telling us your opinion like we give a shit or something!"

Deliberately disregarding Jounouchi once more, Kaiba continued silently assessing Yami, his book completely forgotten. Yami's mere existence in his life served as nothing but irritation, but even though Kaiba was loathe to admit it, the teen helped liven up his day like few others had in the past. There was something almost ridiculously invigorating about sparing with Yami, whether it was verbally or physically; it was all far more enjoyable than it probably should have been.

Deciding that maintaining his silence any further would fuel suspicions, Kaiba retorted, "If you didn't give a shit, you wouldn't be getting so worked up, correct?"

The casual arrogance and vicious expression antagonized Jounouchi without even trying and he threatened, "I'll show you what worked up is," before attempting to lunge out of his seat at Kaiba.

Once again, Honda restrained his best friend and tried to rein him in with words and logic that were promptly ignored. He looked over to Yami for some assistance, but the crimson eyed teen's gaze was firmly trained on Kaiba, as per usual. Sighing to himself in irritation, he pleaded with his eyes at Yuugi and Anzu for some help, even as he tightened his grip and continued fighting to keep Jounouchi in his seat, dodging the occasional stray punch aimed his way in a bid for freedom.

The teacher's arrival into the classroom was largely ignored as everyone was paying more attention to the fight, but it was a sight that was far too common for her to get overly worked up about anymore. Nine years of teaching at Domino High School had desensitized her to random bouts of violence and she merely clapped her hands and loudly commanded, "That's enough of that, you two! Jounouchi-san, Kaiba-san, if you would please cease your morning rituals long enough for class to start, I would appreciate it."

Jounouchi growled in response as he spun around to face his teacher, ready to argue, "Hey, it's not my fault that he's an asshole!"

"Language, Jounouchi-san," the teacher reminded him, although there was no power behind her tired tone as she began calling roll since things had quieted down somewhat.

"Yeah, yeah, yeah," Jounouchi muttered as he angrily crossed his arms over his chest. "Why don't you ever tell him to shut his damn mouth?"

Yami saw that Kaiba had picked up his book and had resumed reading and he could only shake his head at the two. Pushing himself off of the desk, Yami took a seat behind it, deciding that things had calmed to the point that no further interventions were going to be needed. He swore he could almost feel Kaiba's eyes on him, waiting for some sort of reaction, but Yami ignored the sensation; there was no point in adding more fuel to that fire. Besides, what else was there to say?

Homeroom passed by quickly without further incident, something that everyone had learned not to taken for granted. Yuugi had lost count of how many times Jounouchi had been kicked out of class and sent to the principal's office for disrupting lessons.

As class was dismissed, Jounouchi made a pointed show of ignoring Kaiba and exiting from the door at the front of the classroom, something that earned him an eye roll he couldn't see. The immature part of Yami that always seemed to surface couldn't resist the urge to confront Kaiba and his friends could only shake their heads without understanding as he walked over to their nemesis' desk.

"You just can't help yourself, can you?" Yami asked Kaiba as he came to stand next to his desk, watching as the sitting teen packed away his book.

Standing up with a noisy scraping of chair against linoleum floor, Kaiba replied, "You're one to talk, aren't you?"

Keeping pace with Kaiba as they walked to their next class, Yami shrugged as he pointed out, "You don't do yourself any favors by provoking him, Kaiba."

Looking down at the shorter teen, Kaiba looked smug as he repeated a phrase he had used often in their past arguments, "Again, you say that like I care."

"I'm almost starting to think you like riling him up," Yami challenged, smirking as he got a particularly vicious glare. "I mean, you must be getting something out of it, otherwise—"

Cutting Yami off mid-sentence, Kaiba sarcastically shot back, "Oh yes, because I live for that sort of bullshit to get me going."

"Could've fooled me," Yami replied with a grin, silently granting himself a victory point when he heard Kaiba sigh in irritation under his breath.

"That's done easily enough considering you are a fool," Kaiba insulted in a cool tone as they rounded the corner and reached the staircase. "Not much of a challenge…"

"Hey, I am not and you damn well know it!" Yami exclaimed in protest, immediately pulled back into it by the slight. "You're the one getting your kicks out of antagonizing him!"

Shrugging, Kaiba argued, "That is merely your perception of things."

"And what would is your perception of it, oh great and mighty Kaiba?" Yami facetiously questioned.

Turning sharply and almost pinning Yami against the classroom door with the abruptness of his action, Kaiba murmured, "That you seem a hell of a lot more interested in me than your friend," smirking at the scarlet outrage that was so close to him in that moment.

"You would like that, wouldn't you?" Yami retorted, completely unfazed by the lack of distance between them that seemed to be growing smaller by the second.

"Maybe I would," Kaiba suggested in a low tone of voice that sent a shiver through Yami despite himself. It was moments like that when Yami felt an almost physical connection to his rival and everything else had ceased to matter in that moment as his everything was focused on the blue eyed teen in front of him that was so close they were almost touching.

"Is that so?" Yami murmured, getting ready to continue the verbal sparring match when they were both pulled from the moment by the sound of someone clearing their throat.

The pair looked up at the source of interruption and their history teacher was less than surprised at the mirroring looks of irritation on their faces. "While I'm sure this epic battle of wills is of the utmost importance," their teacher joked, "I would appreciate if you would leave it until the end of class."

"Hn," was Kaiba's only response as he pulled away, entering the classroom with only a final warning glance aimed at Yami, smirking when he received one in turn.

Ushering Yami into the classroom, the history teacher could only sigh as he shut the door behind him and tried to start class. It wasn't even worth reprimanding the duo for; it would almost be stranger if the two of them weren't at odds with each other, given their almost legendary bouts of competition for every little thing.

A/N: And so a new story begins. I really wanted to put this one up after I finished Anywhen, but I just couldn't wait. I'm excited for this story's potential and I hope that everyone enjoys this rare sidestep into AU territory.

It'll all start making sense in the next chapter, so I hope that you continue reading this! I can promise that this story will definitely earn its M rating, so you won't be disappointed in that area, either,


A celebration of Jounouchi's birthday takes an unexpected turn when he and Yami make a shocking discovery about Kaiba.

The next chapter will be longer as the plot starts to develop further. I will do my best to get it posted on Sunday, September 20th, so please check back then! In the meantime, I would love to hear your thoughts on this latest story.