Summary: Hatake Kakashi, Copy ninja. Not much is known of him. His past is yet to be discovered.

Warning: Slight Yaoi Iruka/Kakashi much later in the story.

Note: This story is already finished, so I will post the next chapters quickly. Thanks to Masterdeeds for beta-reading!!!!!!!

Disclaimer: Naruto does not belong to me.

The Past Behind the Mask

Chapter One: Dangerous Enemy

Kakashi watched as Sasuke charged his Chidori, sweat dampening his black hair. His brow was furrowed in concentration as he forced his mixed chakra into his left hand. It was his second and last of the day, but, even the first time, he had not been able to take the advantage in a battle against the juunin. Kakashi was barely tired, although the kid was making remarkable progress so fast. He truly was of the Uchiha blood.

Finally managing to stabilize his chakra, Sasuke lunged at Kakashi. His red Sharingan eyes flashed dangerously, reading his sensei's movements easily. But despite that, Kakashi smoothly stepped aside. Using the boy's momentum, he pushed him roughly between the shoulder blades, sending him sprawling into a boulder. Half the rock exploded under the impact of the Chidori, showering the surroundings with debris.

Sasuke hoisted himself up with difficulty, his breathing heavy. His Sharingan had not disappeared yet and he was already mixing more chakra.

"That's enough," Kakashi said as he raised a hand to stop the boy. "You've done enough for today. You'll injure yourself if you continue."

The boy reluctantly let his chakra dissolve and took a deep breath, his eyes reverting back to black pupils. He looked back at the blasted rock and his eyes hardened suddenly.

"It's not strong enough," he muttered sullenly. "The Chidori. It doesn't even compare to Naruto's Rasengan," he added at Kakashi's quirked eyebrow.

"It's strong enough for now. It'll grow with time. It's no good to exert yourself trying to do what you can't yet," replied the juunin, shaking his head.

Sasuke glared at Kakashi furiously.

"It still is too weak." Sasuke bit back.

Kakashi sighed. Sasuke just had no idea how much stronger the Rasengan would be once Naruto learned to perfectly control the Kyubi's chakra, however strong Sasuke would make his Chidori.

"And it always will be, strength wise. Rasengan is a jutsu only Jiraiya and the Fourth managed to learn before Naruto. You can't only depend on Chidori in any case. You have to work on other techniques," Kakashi said with a touch of impatience. He avoided saying that Naruto had only taken about two weeks to learn Rasengan, while even the Fourth had taken three years. Sasuke had enough trouble to cope with the fact that Naruto was becoming much stronger than him.

"I still have trouble copying techniques with the Sharingan. Can't you show me how?" the boy suddenly asked.

"No. Controlling a Sharingan can't be taught, you have to figure it out by yourself. You can't learn hereditary techniques if you aren't of the blood, and teaching's the same thing," Kakashi replied. He turned around then, putting an end to the conversation. He didn't like the way it was headed.

"But you aren't an Uchiha, and you have a Sharingan," he heard Sasuke mutter thoughtfully. Since the boy was speaking to himself, the juunin chose not to comment on that. Besides, it was slippery ground to venture on.

Kakashi disappeared before Sasuke could question him, but he didn't go far. He watched, hidden, as the other boy frowned in thought. Sasuke cast a dark look at the boulder again before walking away.

The juunin sighed. The last thing he wanted was to tell Sasuke about his Sharingan. The boy was too emotionally unstable, torn between his thirst for power and his love of his comrades. And it was ten times worse because of his sudden jealousy of Naruto's strength. It was hard for him to assimilate the fact that Naruto would soon grow much stronger than him, and stay stronger even when they both reach their limits. He might bolt at the slightest thing and run to Orochimaru, and they had to avoid that at all costs. The boy would become a walking monster they'd have to put down.

"He's getting suspicious."

Kakashi sighed again and realized he was fingering his Sharingan over his forehead protector, so he lowered his hand. He had felt Iruka arrive a while ago, but he had waited for the man to speak first.

"You know you should tell him," Iruka said as he sat beside the juunin. "He'll learn of it one way or another. It would be best if it was someone he trusted that broke the news to him."

"I'm not sure he'll still trust me after that. Besides, he's too unstable right now. I'll wait until he's come to terms with his jealousy of Naruto and his unreasonable thirst for power," Kakashi replied. "You don't want him running to Orochimaru."

Iruka shrugged. He had never been able to make Kakashi budge when he decided to be stubborn.

"It's still something to remember. You very nearly became a Missing-nin" the chuunin said coldly. It was not a memory to be treasured.

"No need to remind me," Kakashi grumbled.

Kakashi stared at the Academy with exasperation. He couldn't believe he'd have to waste a year there before he could become a ninja. It was so boring. He already knew all they would teach, he was sure of it!

Someone bumped into him, and he glared at the person angrily. The brown-haired boy caught his balance just in time not to fall on his face in the dirt. He straightened his backpack and smiled sheepishly at Kakashi.

"Sorry! You alright?" the boy asked, misinterpreting Kakashi's expression.

The silver-haired boy snorted in annoyance. "Of course I am. Watch where you walk next time," he added angrily.

"Yeah, sorry again. I'm so excited, you know, becoming a ninja and all!" the brown-haired boy piped up excitedly.

Kakashi ignored the boy and started moving towards the big double doors.

"I'm Umino Iruka! What's your name?" the boy named Iruka asked happily, catching up with the fast walking Kakashi.

The silver-haired boy looked at Iruka in mild surprise. Didn't he see he wanted to be left alone? He was so annoying. Still...he seemed nice.

"Hatake Kakashi," he muttered in answer.

"Then you'll call me Iruka and I'll call you Kakashi!" Iruka cried cheerfully, already liking the other boy.

Kakashi shrugged. If he could make his year less boring, why not? As long as he was not too annoying...

"Come on Kakashi! I bet you can't beat me!"

Kakashi stared annoyingly at Gai. The boy was challenging him AGAIN. He couldn't seem to take 'no' for an answer. He didn't care about his stupid fights; he knew he could beat him anyway. Besides, he'd get in trouble if he fought; Yaiba-sensei had forbidden it when it wasn't during a class. Not that he really minded, but he didn't want to be punished for some stupid fight.

"Leave me alone Gai," Kakashi answered coldly. What and idiot.

"Ha! You're scared of me! You know I'll win! Scaredy cat! The great Kakashi won't even fight! He's just a big-mouth!" Gai cried challengingly.

Kakashi ignored him and kept walking, but soon enough, the insults started to get to him. When Gai threw a rock at him, he snapped.

The black-haired boy barely had the time to dodge the first kunai before he had to worry about three other shurikens. He managed to counter two with his own shurikens but the third imbedded itself in his right shoulder. Kakashi attacked, punching Gai square in the face. The boy was usually better in taijutsu than Kakashi, but the surprise caused by the shurikens had given the silver-haired boy an opening. Gai quickly recovered, however, and Kakashi soon had to abandon taijutsu and use long-distance attacks.

A shower of kunais and shurikens followed, accompanied by a few smoke bombs that allowed Kakashi to land blows with punches and kicks. The silver-haired boy was about to punch Gai in the belly to render him unconscious when two firm hands grabbed him from behind and threw him back, causing him to slam against a tree.

"Just what do you think you're doing, Hatake?" Kakashi's sensei growled, kneeling beside Gai to evaluate his injuries. The boy was covered in deep gashes and a few kunais and shurikens where still stuck in his flesh. "It's alright boy, nothing's serious," the man continued in a more soothing tone, but Gai was already half gone, his eyes only half focused. He blinked confusedly at his teacher.

Yaiba-sensei was a very tall man, lean but incredibly strong. He had a surprising deep voice for a body so lean. His black hair was cut short and streaked with white, even if he was still young. It was said that he was infected with an incurable illness that aged him faster than normal. Right now, his brown eyes were as hard as rocks and furious.

"You come with me, Hatake. We have to bring him to the hospital. You will regret what you've just done," Yaiba-sensei snapped and started running to the hospital, Gai carefully held in his arms. Kakashi followed sullenly and a tad nervously. His sensei's punishments were reputed to be...harsh, to say the least.

A doctor quickly took charge of Gai, followed by a cluster of angry nurses that kept glaring over their shoulders at Kakashi. The boy had difficulty not shying back from those looks.

"Now, what to do with you," Yaiba growled, directing his severe stare to Kakashi.

"So, you're finally done with Yaiba-sensei's punishment?" Iruka joked as he watched a tired Kakashi leave the Academy. The boy had stayed at the Academy five more hours every night to do who-knows-what for a month, and now it was rumoured he was supposed to have finished his punishment. Nobody knew what he was made to do; Kakashi refused to talk about it and asking Yaiba-sensei was out of the question.

"Yeah..." Kakashi mumbled and stumbled back to his house, barely able to stand straight.

"Geez. What'd you nearly kill Gai for anyway?" Iruka asked, hoping to get an answer this time. His friend had been like a closed oyster on that subject; there hadn't been a way to make him talk.

"Idiot insulted me. Did you wait for me the whole five hours?" Kakashi asked a bit incredulously, stepping aside to avoid someone coming the other way but nearly loosing his balance in the process.

"You crazy? Like I'd wait for you for five hours! No, but I decided to come back and check on you," Iruka answered, his tone becoming more affectionate at the end. So Gai had insulted him...and gotten the fight he had wanted, it seemed.

"Thanks," Kakashi whispered. Iruka grinned, thankful that Kakashi's lowered head prevented him from seeing it. The silver-haired boy hated to thank anyone, even his best friend.

"Don't get in trouble like that again, or you won't graduate," Iruka warned, but Kakashi was too tired to reply with his usual 'like it'll happen'.

The next day, Kakashi was the subject of every conversation, like always. Kids clustered together to gossip on the things he had had to do with Yaiba-sensei, even if it was over now. The silver-haired boy appeared rested and well, which surprised a few who had hoped to see him near death.

One kid, when he saw Kakashi, left the group he was impressing and planted himself before the silver-haired boy. He was a bit smaller but stared arrogantly upward as if he had the advantage of height. His hair was pitch-black and unruly, as if wind-blown, and he had defying black eyes.

"So. You're the brat that thinks he can go around killing his comrades, aren't you?" the kid asked with a jerk of the head. He had his arms crossed over his chest and looked everything like a kid looking for a fight.

"Leave me alone, one-eyed brat," Kakashi replied and stepped aside to go around the black-haired boy.

The boy starting shaking at the insult. He was a coward at heart, but this time he was shaking with anger. His name was Uchiha Haji, and he was born with what was said to be the purest Uchiha blood. The first time he had opened his eyes, he had already been able to use the Sharingan. But that was why his clan had called him Haji, 'shame', and that the kids had nicknamed him one-eyed. Although he was strong and of the purest Uchiha blood, he only had one Sharingan. That was considered a great disgrace and his mother had called him Haji so that he'd feel shame forever for having only one Sharingan while still being so talented.

"You won't get away with that!" Haji yelled at Kakashi's back. The silver-haired boy stopped and half turned his head.

"So that's it. You didn't want to confront me while I was being punished so that Yaiba-sensei couldn't blame you for harassing me, but now that it's over, you want to pick a fight so it'll look like I started it and be punished again," Kakashi said, his temper rising despite his usual calm.

Haji was about to say something back when Yaiba-sensei appeared.

"Come on kids, you'll be late. Hurry up," he ordered, motioning them inside.

The two boys obeyed, ostentatiously not looking at each other. When Kakashi sat beside Iruka, the brown-haired boy looked from him to Haji and back again and frowned.

"What did you do, this time? Uchiha is practically glaring at you! If looks could kill, you'd be dead three times already!" the brown-haired boy said as he watched Haji from out of the corner of his eye.

"The idiot annoyed me." Kakashi answered, lounging in the uncomfortable chair.

"Don't tell me you called him one-eyed. He won't leave you alone you know. Everyone who calls him that pays for it, and he never gets caught. You better watch out," Iruka warned, his tone becoming worried. Few dared to call Haji one-eyed to his face, and those who had regretted it.

Kakashi shrugged, apparently unconcerned, but he was worried inwardly. Haji was much stronger than him when he used his Sharingan. If he ever had to fight, he'd lose for sure.

The silver-haired boy looked at Haji over Iruka's shoulder, and a chill went down his spine. He had made himself a dangerous enemy, and however long it would take, Haji would make him pay.

TBC

Yaiba: Edge

Haji: Shame

There, first chapter! Hope you like it. I'd like to say once again that everything and everyone except the usual Naruto cast is of my invention.

A-chan