A/N: This is a new multi-chapter fanfiction that I am writing about Yukio and Rin. As a warning this is an AU fic, where Yukio and Rin are not brothers, where they just meet at the age of sixteen, and where their first impressions of one another don't start off good. This fic is also rated mature for a reason, things will be happening in the future that might make some viewers uncomfortable, so if you are a person who finds boys having sexual or romantic relations, please don't start this fic. Also, I will not be posting author's notes at the beginning of every chapter when I start posting chapters, so you don't have to worry about that. Thank you for reading! Please review!

Chapter 1: Didn't Have To Throw A Damn Stapler At Me.

An uproar of pointless chatter assaulted Yukio from all sides as he swaggered through the corridors of True Cross Academy. He inwardly tisked as he watched the uniform clad girls gather like ants by the big bay windows, squealing to their hearts content.

A new transfer student at True Cross Academy was not rare by any means, yet they all acted as if this guy was a teen idol of something; it highly confused and annoyed him.

"Where is he? Where is he? I don't see him yet!"

"That's because your big head is the way Ami!"

"Oh shut up! You're the one hogging the window!"

He almost told all of them to go back to class, he was a prefect after all, but what good would that do? They would continue with their boarder line abnormal watching.

With a quicker pace in his step and the pushing up of his glasses, he left all thoughts of the squealing girls behind him and went deeper into the less habitual part of the school, where bright warm crème colors transformed in to dark reds, purples, and black.

He rounded a couple of corners, stopping in front of a huge mahogany door. He straightened his posture, gave his shoulders an experimental roll, and brushed off his school uniform with a couple flicks of the wrist. He knocked three times, just like how he was asked, and heard distant chattering inside. Two voices to be exact, one was unfamiliar, and Yukio knotted his brows in confusion. They sounded happy as one gave an obnoxious laugh.

"Yukio? That you? What are you doing on the other side of the door! Come in!" Mr. Fujimoto's voice bellowed out. Even with the door shut it echoed through the hallway.

He slowly walked in the room that oddly reminded him of autumn, keeping his eyes modestly on the floor until he shut it with a quiet little 'click'. What he saw when he looked up surprised him.

A boy, about his age, perched lazily on the front of Mr. Fujimoto's desk. He was dressed in dark wash denim jeans that sagged, showing off his flannel boxers. He wore a white leather jacket with a black dress shirt that was half tucked in half tucked out, and to finish the assemble off, a red loose tie.

Yukio visibly cringed at the boy. Was this his attempt at making a school uniform? Sorry, a tie doesn't make you look any more professional, he thought.

The boy took notice of Yukio's cringe and the toothy smile that had occupied his face turned into a calculating frown, as his eyes dark blue eyes narrowed.

They stared at one another, both measuring each other up, testosterone crackled in the negatively charged air.

Not once did Yukio think of what this boy was doing here, in his bosses' office, he actually forgot that he was there himself. There was just something about the boy that didn't seem right that just set him off. The way he came off as cocky and arrogant, Yukio thought, had something to do with it.

"Have something to say four eyes?" The boy said. His voice was low, threatening. Yukio had to repress the urge to roll his eyes. He gave a half assed laugh, as if to say, 'really? That's the best you got?"

Before he could make his own witty comeback, a tense cough alerted him back into his surroundings. He blushed slightly as he remembered where he was and in whose presences he was in.

Clearing his throat and pushing up his glasses he maintained the professional Yukio that everyone recognized. He rounded his sight onto Mr. Fujimoto who had a faint knowing smirk on his face. Yukio could feel other eyes bearing into him, but ignored the compulsion to stare daggers back.

"Sir, you asked to see me?" Shiro leaned back into his chair, as his fingers intertwined on his desk.

"Ah, yes Yukio, I wanted you to meet and get acquainted with True Cross Academy's new transfer student…my son."

That's when he couldn't help but to look at the boy. This couldn't be- "Your son?" He looked back. "Wait! You have a son!" The person in question slyly smiled, enjoying seeing Yukio confused.

"You both look nothing alike." This- thing couldn't be related to a guy like Shiro Fujimoto! This delinquent looking thug couldn't-

"Yukio Yukimura, meet Rin Okumura, my son."

Yukio told himself that he had to look stupid with his mouth agape, but he couldn't help it. He was supposed to room with this-guy?

Light laughter filled the room. "Geez, now he's gonna start drooling everywhere." Rin hopped off the desk and threw himself into one of the plushy chairs in front of Mr. Fujimoto's desk. "Nice to meet you too, Yukio Yukimura." Rin said sarcastically. Yukio ignored the barb, and sat down also in one of the plushy chairs.

"Why didn't you tell me? Did you even tell anyone?" He asked quietly, he felt betrayed somehow. He never got told of this 'sons' existence, not like he would want to know now. Shiro shrugged his shoulders like never telling anyone you had a son wasn't that big of a deal.

"You never asked."

"Sir!"

"Better deal than what I got, all I ever heard about growing up was Yukio this, Yukio that, give me a fucking break." Rin spoke up, playing with the ends of his unruly navy blue hair as if they were the most interesting things in the world.

"At first I was like, 'No way! No one so badass could be a dorky four eyes-Ouch! What the hell was that for!"

Shiro had thrown a stapler that hit Rin right in the middle of the forehead. A red whelp had even already begun to form. Rin rubbed frantically at the red whelp. "That's probably gonna bruise you crazy old man!"

"Watch your mouth Rin. That's no way to talk in front of a guest or, in a matter of fact in school now that you're enrolled. I don't need you getting kicked out of this one."

Rin murmured something under his breath as he crossed his arms and huffed out a frustrated breath. "Didn't have to throw a damn stapler at me."

"Yukio I apologize in advance for my son's crazy antics, but there is a reason why I am asking you to be his… guardian of sorts." Rin mumbled something under his breath again, something to the effect of, 'guardian my ass'.

"Rin is special, as well as being a trouble maker. He knows that this school is not just a school and he knows about demons, he can see them. Not only do I want you to keep an eye on him when I can't, but I want you to train him to become an exorcist."

Yukio was speechless, he taught students and handed out exams, but to actually train. He didn't believe he was that good.

"Sir I'm not sure if I can-"

"I know it's a lot to have handed to you but I believe that you are the best for Rin to learn off of and from."

Yukio was still skeptical, but nodded his head in agreement. If Mr. Fujimoto thought he could do it, then he would try his best not to let him down.

"I'll do it sir. Your faith in me is very flattering."

Shiro clapped his hands together in joy as he gave Yukio a huge smile.

"Thank you Yukio. I greatly appreciate it." Yukio nodded in acceptance, his ego swelling in pride.

"Now what are we going to do with you troublemaker?" Shiro addressed his son with amused mocking arrogance. Rin shrugged, his hand propping his head up with a tilt, a look of pure boredom written on his face.

"I don't know-send me off somewhere actually cool."

Shiro's face morphed into fake mortification. "Are you saying that this place isn't cool? It's the coolest place on Earth!" He gestured out with his hands.

"Whatever you say old man."

He smiled fondly at Rin, like a father would, and it truly fascinated Yukio, as he had never had one.

"Sir, are we done here? I have a class to teach in-"He looked casually at his watch, "fifteen minutes and my classroom is at the other end of the school."

From the corner of his eye he saw Rin visibly stiffen. "Old man-please don't tell me-"

"Rin, meet one of your new teachers!"

Rin looked horror stricken, his cheeks turning slightly pink.

"But, but- I'm older than him!" Rin pointed his finger accusingly at Yukio. It was Yukio's turn to look horror stricken.

"You? Older than me?" Yukio said astoundingly.

"Yes me older than you!" Rin snarled back.

Shiro must have thought the exchange was hilarious, as he was hunched over clutching his stomach.

"You boys don't want to be late to class do you?"

Yukio shook his head, staring daggers at the old man. He had a very worrying feeling that things were about to change. What he couldn't figure out if it was for the best or worst.