Author's Notes: This story is entirely AU, that is there are no Ancient Egyptian spirits, no Millennium items and no Duel Monsters (sorry if that upsets some people, but I cannot write anything to do with Duel Monster battles!)
Next, this is a yaoi fan fiction. For those of you who don't know, yaoi means boyxboy relationships, so turn back now if you do not like this sort of thing.
The rating stands at the moment at PG-13. There may, and I stress the word may, be a lemon a few chapters on, and in that case I will have to raise the rating.
Some of the characters, Mokuba and Yami mostly, will be OOC. Yami is shier and although he is confident at times, be prepared for some major blushing around Mokuba. Mokuba is more confident around Yami, and you may want to take notice to the pairing order in the summary...
Another thing you may want to be aware of is that in my story, Mokuba is actually 1 year older than Yugi.
Right, sorry about the long list of A/N, but it had to be done. Anyway, on with the story now.

Disclaimer: I do not own Yu-Gi-Oh!

Animal Instincts

Chapter 1

Beep Beep!

A low groan emitted from the bed near the bedside cabinet. But it was empty... the owner of the bed (and groan) was in a heap on the floor.

Beep Beep!

This time, the voice gave an annoyed "Argh!" as a long slender arm reached up to the bedside cabinet from the floor and blindly groped around for the alarm clock.

Finally switching off the annoying beeping, the person, boy to be exact, got up from the ground, slightly disorientated as he wondered how he had got there. Then he remembered. He had been having an... interesting dream. He couldn't see what was actually happening, all he knew was that it was good.
He blushed as the dream came back to him. The guy who was with Yami certainly knew what he was doing.
Yes, guy. Yami was very openly gay, and it obviously didn't bother him.

As though to bring him out of his thoughts, Yami heard noises from the bedroom next door.
His 14 year old brother Yugi was already up, or at least thinking about getting up. Yami had always referred to Yugi as his baby brother, despite Yugi only being two years younger than him, but Yami knew that it infuriated the younger teen so much, so had kept it up.
Even though Yami irritated his brother on purpose, they both loved each other very much.

Their mother had died shortly after giving birth to Yugi, but the strange thing was that she wasn't exhausted at all, she was actually really healthy. So the boys had been motherless... natural, suicide or murder, take your pick.
Their father had then left them with their grandfather when Yami was 6 years old and Yugi 4. He had used the excuse that grandpa was very lonely so needed company, but Yami knew the truth. His father either couldn't handle them, or just couldn't stand his own sons being around him. So the two boys had been abandoned.

Yami was bought out of his thoughts again by his brother. He heard Yugi get up and yawn loudly and Yami immediately dropped the bed covers that he was holding, intending to make the bed, to rush into the bathroom before his brother.
As soon as he saw Yugi's shadow coming round the corner, he rushed out of his room and into the bathroom. He vaguely heard a whine from his brother before he closed the door.

"Yami!" Yugi yelled, pounding on the door.

"Yes, Yugi?" Yami asked innocently from in the bathroom, not poking his head outside just in case.

"Yami, you knew I was going in there first," Yugi whined to his older-by-two-years brother. "Argh! You do this every morning!" he yelled at the door.

He heard the lock click and thought he had won, but Yami just poked his head round the door wearing his trademark smirk and said "well you'll be used it by now then." Yami closed the door again, locked it and Yugi heard the sound of running water.

'Great,' Yugi thought to himself. 'I'm not getting in there for a while.'

Finally, about an hour later, the two boys were ready for school. The minute Yami had emerged from the bathroom, Yugi sped in. Yami chuckled and then laughed even harder when he heard Yugi give a relieved sigh. He could only imagine what would have happened if he had been just one minute longer.
Yami and Yugi said good-bye to their grandfather who was sitting at the dining room table reading the newspaper.

It was the beginning of another half term, and the short two week break had ended. Although the boys were a bit annoyed to be going back to school having just gotten used to the holidays, they could not deny that they had missed their friends, as they hadn't seen them throughout the whole of the two weeks' holiday.

As they entered the grounds they heard a familiar voice calling them. "Hey! Yami, Yug!"It was Joey Wheeler, one of Yami and Yugi's closest friends. He and his sister, Serenity, lived separately after the divorce of their parents. Even though they only saw each other about once a week, the bond between each other had always been strong and still was.

"Hey, Joey!" both brothers greeted. "Have you seen Tristan at all today?" Yugi asked.
Tristan was also one of their close friends, but not as close as Joey who had known Yami since he was 6 years old, and Yugi 4.

"No, but he's probably hanging around the girls, looking if he can find a date right at the beginning of term as usual."
The three teens laughed. At that moment, a huge limo pulled up outside the school.
"Oh, great. Moneybags is here," Joey said.

'Moneybags' was Seto Kaiba. After his step-father had died, he had inherited KaibaCorp., and so was extremely rich, and owned his own company, even though he was only 16 years old.

Kaiba stepped out of the stretch limo and almost immediately a group of ecstatic fan girls rushed up to the rich CEO. A small chuckle could be heard behind Kaiba and as the group moved on, it revealed a young boy, about 15 years old standing by the door of the limo.

Yami found himself staring captivated by this young boy. He had waist length raven black hair, and although he was still in his early teens, his face held a mysteriousness and deviousness that excited Yami. He did look oddly familiar...

"You okay, big bro?" the smaller boy asked grinning after his brother. His voice made Yami smile; so much so that he didn't even realise what the object of his affections had said until Kaiba answered.

"Mokuba. Go to reception as soon as the bell rings for class. Tell them that you're new, okay? I'll try to see you at lunch. Have fun on your first day."
Kaiba had barely gotten out the last words before the fan girls rushed him off again, much to Joey's delight.

Reality suddenly hit Yami. That boy was Mokuba? As in the small boy he hadn't seen for about two years? The last time he had seen him was when he came to the video store that Yami and Yugi's grandfather ran. Yugi and Mokuba had been friends before, so Yugi had asked Mokuba to stay for dinner. They were quite close, but after Mokuba left Domino to go to Tokyo with his brother, they grew apart.

Now, here he was again. Yami couldn't believe how he had changed. Gone was the small, timid boy, and in his place stood a young man, confident of almost everything he did. The two years away obviously did a lot for his attitude, but also for his looks.

The school uniform had been abandoned (some of the students complained that the uniform was bordering on child abuse!) and right now, Yami thanked every god he could think of for the school council who decided it. Mokuba was wearing a short sleeved black shirt that was under a hooded crimson waistcoat. He wore tight fitting black leather pants, and although it left little to the imagination, gods, was Yami's imagination reeling!

"Uh, Yami! Hello?" Yugi's hand waving in front of his face bought Yami out of his reverie.
"Huh! What!" he asked intelligently.
"You okay, Yami?" Joey asked, grinning. "You spaced out for a while there."

"Oh. Um, I was just thinking," Yami answered rubbing the back of his neck in embarrassment.

"Uh huh," Yugi answered, raising an eyebrow in suspicion.

The morning passed by uneventfully. Yami had not seen Mokuba since that morning, but he couldn't help seeing the boy in all his glory whenever he closed his eyes.
Yami wasn't aware of it, but he grinned every time he thought of the young man - something that didn't go unnoticed by his younger brother and friends.

"Hey, Yami!" Tristan yelled in Yami's ear when he zoned out again.
Yami looked round at Tristan, the goofy grin still on his face. The others looked at him with some amusement.

"What's up with you today, man?" Tristan asked. He could have sounded concerned, but the grin on his face betrayed him.

In reply, Yami's smile just grew and he let out a long sigh. "Nothing. Just... nothing," he answered, the stupid grin still on his face.

Yugi leant over to Joey and Tristan and whispered something to them about dreaming and moans coming from Yami's room last night. The other two looked at Yami with wide eyes.

"Hey, guys," came a familiar voice. The sane people, (well, sane at that moment, with Yami still lost in his dream world), looked up and saw Mokuba. "Mind if I sit with you?" the raven haired boy asked.

"Not at all, Mokuba," Yugi replied.

"Where's Moneybags?" Joey asked.

"Um, he's in the library or something. He said something about it's the only place those fan girls wouldn't find him," Mokuba chuckled and Joey looked delighted at the thought of the great Seto Kaiba having to run from a bunch of crazed girls.

"Uh, what's going on with Yami?" Mokuba asked, looking slightly concerned for the boy he had sat next to.

"Well, we're not completely sure," Tristan answered. "Although Yugi thinks it may have something to do with a dream he had about some guy last night."

"Oh, I know those," Mokuba smirked knowingly.

This shocked everyone.
"You mean you're... " Joey stammered, more than a little shocked.

Mokuba nodded, but didn't seem in the least embarrassed.
Instead, he turned to Yami and waved his hand in front of his face. "Yami. Oh, Yami."

When that didn't work, Mokuba simply flicked the other on the nose.
"Huh? What... " Yami looked around, as if to find someone about to attack him.

"Finally, you're back in the world of the living!" Mokuba exclaimed sarcastically.

At the sound of his voice, Yami looked round to see dark grey eyes sparkling with amusement staring back at him.
"Mokuba," he squeaked. He couldn't help a small blush tinting his cheeks.

Joey howled with laughter. "Oh man, I wish I had my camera! First Yami goes all dreamy on us, then he blushes!" Joey snorted as he tried to control his laughter, but it only made him cackle even harder.

Mokuba smiled also, making Yami blush even more. Gods, did this kid know what he did to him?

Well, there's the first chapter. Hoped you liked it and please leave a review!