Disclaimer: I do not own any of these characters. They are all to their respective and original owners. I am simply borrowing them for my own amusement. At the end of the day, I own nothing.

Meanwhile, back in the regular academy, the fixation of Rin's thoughts returned the favor. Mephisto sat in his chair, staring at a large amount of paperwork that he was supposed to have done on the progress of the pages as well as whether to confirm their ExWire exams a few weeks from now or to prolong their training. Mephisto had honestly started his paperwork with all intention of finishing quickly and efficiently with plenty of time for tea at noon.

However, as the clock ticked past one, his mind was caught up with his most curious little brother. The boy was so feral and raw in his emotions, open to sharing and objectifying his opinions as he saw fit without parameters. The outrageous teen was entirely his opposite. Where Rin would happily fly into action without reservation in a very gung-ho manner, the older demon felt that flying into action was foolish, resolute in the idea that each step required careful calculation and time to move all the pieces into place to ensure success. His excessive planning gave him a unique sense of omnipotence in which he basked in, loving the feel of being in total control without unplanned interventions and interferences. Yet, in the same sense, he didn't enjoy being so far ahead of everyone. It left no room for shock and pleasure outside of the amusement of pulling at the strings of those caught in his marionette schemes.

That is, until his older Okumura twin came into the picture. The child was filled with infinite surprises that defied each side of his birth in turn. Truly, he was a mixture of contradictions that captivated Mephisto far more than any experiment he had ever conducted. The boy eluded the madness and evil of his demonic heart while thwarting the corruptibility and demand of his human body.

In truth, Rin was a picture of virtue, naivety, and innocence aside from the obvious strains and desires of the teenage brain. And this only added to the sheer contrast between Mephisto and Rin that drove the older demon partially mad with unanswered scientific and philosophical questions. The events from the previous night had only enhanced his curiosity, unveiling a new level of mystery within his little demon enigma.

'Tou-san..tou-san..come back..' Rin's muffled cries replayed in Mephisto's mind. The weakness the younger demon had shown was fascinating. It was not often Mephisto had seen such weakness, most in his presence took extra care to guard their feelings from his watchful eye. The boy was more distraught than the King of Time had ever seen anyone before and the sheer magnitude of his depression pulled a sense of brotherly concern from Mephisto that he had never felt for any of his brothers. It was nearly terrifying in how unfamiliar and strange the feeling was.

His curiosity peaked as he stared out the window, seeing the object of his intense speculation strolling exhaustedly beside his glass-wearing counterpart. It was quite late in the day for them to be heading into the Academy and very early in the day for them to be heading to cram school. A laugh escaped from his lips as he leaned into his palm, watching the boy who seemed too tired to even hide his tail, though he was in plain sight of the Academy's windows. The older demon's laughter came to a halt, peering at the tail as if he could hide it with his eyes. A tick formed in his eyebrow as Rin parted from his brother, turning his back to the school and standing there for a moment, his still tail flickering behind him. Mephisto shook his head and closed his eyes, feeling a vein work it's way to the surface of his forehead, the boy's careless manner was going to expose his true identity in no time.

Mephisto opened his eyes, seeing the boy was now gone. Hopefully, no one from the school had seen the wandering child with a long, black, wriggling appendage sprouting from the base of his spine. The key word being hopefully. A plan began to form in his brain, stemming from the need to preserve his plans for his little brother and feed his own curiosity at the puzzle like brother he indeed had. A scheming smile spread across his face.

Rin walked out of his dorm on time the next morning. He stretched and yawned, looking up at the morning sky. Yukio was still inside, not skipping breakfast like his brother. Rin's stomach felt uneasy for some reason, making it hard to eat or think. He let out a sigh, scratching his head and beginning to walk to the academy, his tail slipping to tuck itself around his waist.

The demon made his way into his homeroom, lounging in the desk closest to the windows and farthest from the front. Sitting in a seat by the windows made him feel like a manga hero, one of the really cool ones who simply stared out the window, looking attractive and aloof, waiting for something awesome to happen. Every manga he had ever read, the main super awesome guy always looked out the window. And good things always came to him, unlike in Rin's shit storm of a life.

Rin's day dreaming of what his life would be like had he become an attractive manga character who gets the girl and saves the day distracted him through half of class before a piece of paper smacked him in the forehead. He let out a yelp, rubbing his forehead. His loud interruption led to him receiving many confused and annoyed looks from his snotty peers and a reprimand from his doddering sensei, causing his face to grow crimson and heated. The class' attention turned away from him and he picked up the offensive piece of paper. It was folded in the shape of a football with English sprawled all over it. Rin stared at it, perplexed, before unfolding it.

Fortunately, his English was fairly decent, even considering how boring his English sensei was in middle school as well as the one at True Cross. It read in looping, calligraphic writing:

Pay attention, Rin.

P.S. I can see your tail wriggling beneath

your shirt. I would suggest being more

careful. Somebody might see it.

Rin instantly stilled his unconsciously shifting tail and looked around for the note's sender. The hair on the back of his neck stood on end. Whom ever it was, they were watching him closely and they had seen his tail. He could practically feel Yukio and Mephisto's wrath heating the air around him for such a slip up. A regular student knowing about his secret could spell his death; or worse, getting kicked out of the exorcist program.

An older looking teen in a desk close to him caught his eye. The boy was staring very pointedly at him with a large arrogant grin across his face. Rin guessed it was this shoulder-length, obnoxiously bright yellow-haired boy who had tossed him the note. The guy's fiery orange eyes stared at Rin amusedly in a way that seemed familiar. Rin narrowed his eyes, pointing at himself then the paper then at the boy, who nodded, confirming it was from him. The young demon frantically jotted down a reply:

Who are you? How do you know about me?

He folded the paper into a square and flicked it at the blonde's desk. He read the note, his smile growing into a full blown grin.

Mephisto couldn't believe how easy it was to throw Rin's guard up and grab his attention. Mephisto was satisfied that in this form he could get to know his ward in ways he could not in his true form. He could get the other boy to trust him, befriend him, learn from him, listen to him, all as easy as taking candy from a baby. It was truly going to be a fun experiment in manipulation.

The older demon paused before sending a reply back on another football-shaped note. He didn't know if it was really a good idea to use his true name as a mock alias. If Yukio or one of the professors were to recognize him by his true name, Samael, the disguise would be worthless in trying to improve Rin's grades and performance. Mephisto shook his head, deciding his true Demon King name was buried enough to not ring any bells in any of the exorcists. He wrote back to Rin:

Samael Thyme. I am knowledgeable in many things.

Rin scowled and glared at this 'Samael' character. He quickly scribbled another reply.

Baka, how do you know my secret?

Mephisto laughed in his much softer, young, fake voice and turned slightly to catch Rin's eyes. He had the full intention to get the boy to tolerate him and even enjoy him enough to be his acquaintance, and thus, be able to keep tabs on him at all times. But he figured he could have a little fun and be a little obnoxious along the way. He didn't get to be childish very often and, if he was going to be stuck back in a teenage body, he was going to soak up the privileges.

Rin was looking back at him, completely bewildered and Mephisto repressed the urge to laugh again. He was quite ready to toy with his ward while he kept such a close eye on him. Mephisto let his own tail peak out from beneath his white school shirt, assuring that Rin could only catch a glimpse of it before hiding it again as if it had never been there.

If Rin knew he was a demon to, it would pique the boy's interest and make him even more interested and confused. Mephisto, or Samael in this form, chuckled a bit as Rin's eyes widened and brows raised as if questioning the validity of the appendage that had peeked out from beneath that thin, white fabric.

'Samael' shrugged and turned away from Rin, completely ignoring the dumbfounded look upon the Okumura's face as well as several questioning notes that were sent flying at him throughout the remainder of class. Rin could have sworn he had seen a tail slipping out of Samael's shirt and he was entirely sure he was going crazy because it was impossible for another humanoid demon to be attending True Cross. Well, not impossible, but he would have heard something about it from Yukio or one of the other exorcist in charge, or at the very least, Mephisto. And if this kid was a demon, that would mean he was a very powerful one. Or at least, from his understanding of the demon hierarchy, the only demon humanoids were the offspring of very powerful demons who were able to cross between Gehenna and Assiah, such as Satan.

All these thoughts were put into question form and sent flying at Samael's head; however, the mysterious teen seemed to be focused on whatever it was the teacher was saying. Rin's questions were left unanswered all day even though the two teens had every class together and sat within feet of each other in every single one. Rin had tried to question Samael multiple times but the blonde disappeared quickly after every class and seemed to magically pop into his desk just as the bell rang. He also ignore any notes shot at the back of his head, which was pissing Rin off. By the end of the school day, the spawn of Satan had become extremely annoyed with the enigmatic teen and sought the source of his rage out before cram school started.

However, no amount of scouring uncovered Samael until Rin rushed into Yukio's classroom just as his twin began lecturing. His blonde target was sitting in one of the center rows alone, ignoring Rin and looking at Yukio in anticipation. Yukio gave his brother a miniature lecture as well as a disapproving frown before ordering him to sit down. The scolded noiret took his normal seat by Sheimi, settling in and listening to his brother's droning with innate, uncharacteristic attention in order to avoid punching or cussing at the kid behind him.

Yet, when a note from the infuriating guy hit Rin in the arm, his fury subsided, evolving to curiosity and satisfaction, or well, hope, that Samael was going to answer his questions.

I hope you are paying very close attention to the names of the healing herbs and their specific uses. They will be on the ExWire written exam. Just saying.

Exasperation hit Rin and he felt a vein pop in his forehead. He narrowed his eyes in confusion and frustration, writing back asking how Samael knew what would be on the exam as well as why the teen had been ignoring Rin up until now before casually tossing his hasty note over his shoulder when Yukio turned his back. Samael caught it absently while Suguro, Shura, and Konekomaru watched the exchange of notes questioningly.

A minute later, a tiny scrap was sent spiraling back at Rin, who grabbed it before it skidded off the table.

I told you I was knowledgable in many things.

Rin scowled again, hating how aloof the other teen was trying to be. He wrote back, viciously chucking the poor piece of paper at Samael.

Who the hell are you, baka? And I don't mean your name.

A stifled chuckle came from behind him as well as another note. Mephisto knew this was definitely going to get Rin's attention and he reveled in the fun of his new game.

I am a demon.

Bright blue eyes rolled, the word 'duh' appearing in his mind while remembering the tail that had sprouted from the other teen's behind earlier. Rin turned to stare at the boy behind him. He took notice for the first time of Samael's ears and smiling fangs, confirming that this was most definitely a demon and that this was a powerful demon who had infiltrated True Cross somehow without raising a single alarm.

This was bad.

Rin's hair bristled and he ground his teeth, fighting the urge to reach for his sword. He wondered why no one but him had noticed the infiltrator or, if the others knew, why he hadn't been told that there would be a new student of such magnitude here.

Rin's eyes narrowed dangerously, the purple in his irises that Mephisto had noticed the other night growing a deep shade of red. Samael, a.k.a. Mephisto, suppressed a smile and winked, making his escape from Rin's angry, bewildered eyes as Yukio dismissed the class. The older Okumura looked at his brother in surprise, not having realised class had gone by so quickly. The twin gave him a confused look but Rin had already jumped up and rushed after Samael, intending to get answers and knocking into Kamiki and Sheimi in the process. He heard a yelp of anger and a cry of concern, shouting an apology over his shoulder as he rushed after the blonde demon, wondering if he should have grabbed Yukio to come with him to catch the infiltrator. Samael entered a side door in the long cram school hallway, letting out a cackle.

Rin barged through the random door, skidding to a stop with haughty eyes, chest heaving slightly and hand ready to let Kurikara out. His target sat unaffected on a desk, a smirk spread across his pale face.

"How did you get into True Cross, dammit? Who are you?" Rin asked, his voice was loud and piercing in a way that reminded Mephisto of their father. Mephisto took note of the intrigue and anger in Rin's eyes, knowing he had best explain himself before he pushed the boy too far. He wanted to make the boy his friend not his enemy no matter how fun making Rin mad was or how easy it was.

Though, he was sure he could push a little more, Rin seemed to respond to anger better anyway. Seeing as it's a feeling Rin's extremely familiar with, Mephisto wasn't surprised.

Samael shrugged and smiled, shaking his head patronizingly.

"Haven't I already told you? I'm Samael Thyme, a demon. I'm your classmate from now on. And, obviously, I got in because I'm a student here to learn." He yawned, giving Rin a droopy eyed look. "You really don't pay attention, do you? No wonder you're failing your classes, or at least from what I've heard from other students, you are. You're just the class clown."

Rin growled and lunged to punch the infuriating blonde in the face. He was easily evaded, being left reeling to catch himself from falling into the desk the boy had been sitting on. Rin turned and glared at Samael who was laughing at the Okumura's clear irritation. Samael's laughing subsided as he sat on another desk and crossed his legs. Mephisto decided it was time to stop and lay out his true intent before Rin got too enraged.

"You know," he began, "If you're having trouble, I could tutor you for the ExWire exam. And I could look out for you at the Academy since you're so good at trying to blow your cover." Mephisto stared at the boy who seemed dumbfounded by the offer, his fisted hands unclenched and his mouth dropped.

Rin made motions to speak but couldn't find words for the idiocy he was hearing. The mysterious kid in front of him was clearly a nut case, showing up out of no where, knowing his secret, calling him an idiot, pissing him off, then offering to help him as if he hadn't just done all that. Rin almost felt the need to laugh at the insanity of it and crossed his arms, glaring.

"Tutor me? Look out for me?" Rin's face was a mixture of interest, disbelief, and, fading but present, anger. "Chh, baka," he replied. "Why would I want your help? Why are you here? I'm supposed to be the only demon at True Cross, at least student wise."

"I wanted to go here, I talked to Mephisto, paid my tuition, here I am." Samael snarkily replied, leaning back and forth on his perch.

"Fair enough. Then, why do you want to tutor me? You don't know me. You called me stupid. You've missed an entire month of classes and yet you think you know more than me over this stuff, you cocky bastard. You've been a jerk the entire day I've known you!" Rin glared and threw his hands up exasperatedly. Samael tapped his chin as if milling over Rin's words.

"I suppose you're right on some of that but, you see, I already know most of this stuff and I'm just here for the certification. And as for not knowing you and what not, we're both demons which instills camaraderie and I'm a nice guy so I'm happy to help out a fellow struggling classmate." Samael smiled a softer smile than he had before, hoping to warm the boy up to the idea of accepting his help. Rin looked as if he was thinking it over and Samael felt his tail began to wiggle in anticipation.

If Rin said no, Mephisto's plan would take longer to put into play and he would be disappointed in himself for ruining his experiment because he wanted to enjoy some childish taunting.

However, Rin surprised him.

"Okay. But, only because I really don't understand most of my classes," Rin said, assuring the boy knew he was still suspicious of him. Samael raised his hands in surrender.

"Use me as you will, Okumura-kun." Mephisto-slash-Samael hopped off of the desk he had been perched on and held out his hand to his ward-slash-tutee. Rin gave him a look and Samael rolled his eyes, motioning his out stretched hand a bit to prompt Rin to take it. The boy hesitantly did and Samael beemed. "The deal is made. You can call me Sam, by the way. It sounds a little more normal than Samael." Rin shook his hand and knots built in Mephisto's stomach. Touching Rin's skin like this felt as intimate as their embrace on the roof had felt.

Any form of contact with Rin felt intimate because of its rarity. Mephisto let go of the pale hand for fear he would vomit from the sensation of the soft, human skin against his. Rin nodded as his hand was dropped, staying silent as he gave Samael a continuous suspicion-filled stare. "Well, bye. See you tomorrow, Okumura-kun."

Mephisto walked out of the room nonchalantly, even if his insides were tensing and recoiling as if he had been electrocuted. He couldn't describe the unusualness of the feeling and it befuddled him. He teleported back to his office and transformed back into his regular form. The suspense in his stomach subsided and he chalked up to relief at having Rin follow along with his plan. He had after all had his doubts on Rin's temperament toward another demon. Being Satan's spawn, Mephisto had expected Rin to have inherited his territorial nature and quick-to-anger attitude. One of the two had proven true and Mephisto had expected the other to follow suit.

With a shake of his purple hair, the older demon put his worries and musings to rest, knowing that his plan would work out as most of his plans generally did. He looked forward to experiencing what his ward experienced and seeing everything the boy couldn't hide in normal situations. His experiment would be an interesting one indeed.