Disclaimer: I do not own Ao No Exorcist : 3 I only own my OC :D

AN: Hello! Thank you for clicking on this fanfic :) This is my first ANE fanfic, and I wasn't planning to post it up for a while, but I'm feeling good and decided to go ahead and put the first chapter up. It's rated T because of some violence and a little gore, but I don't think there's anything too horrendous in here. It does have an OC, so if it's not your thing, just click out of it :) Also important, thanks to ChaoticDiamond because much of why I wrote this was based on her support :) Pairings are still undecided, and I'm open to suggestions. This is probably going to follow the anime, I'm not sure yet. I hope you enjoy the story!

Rin first heard the whistle of something flying through the air, followed by a dull thud and sickening splat. He frowned when he turned to see a bunch of teens messing around, in particular a white haired one holding a simple crossbow and notching another wooden arrow. The ground in front of them was littered with pigeon corpses embedded with arrows and he paused with his bike. He heard a whine by his side and turned to look at the black dog at his side. She had sharp ears which were slightly lowered, a slender muzzle, which he knew hid sharp, sharp teeth and incredibly strong jaws. The shiny black fur was thick and trailed out all the way to her tail, which was bushy and a usually very expressive tail, but was now trailing slightly higher than her hind legs. To be honest, Rin had always thought she looked more like a wolf, especially the eyes that had earned the black dog her name: Taiyoume, with her yellow eyes. Most people were afraid of Tai when they first met her, her razor sharp teeth and scary looking beast features screamed dangerous wild animal, but he had never, ever, felt threatened by Tai. He just went with his instincts, and they told him she wasn't going to hurt him.

She cocked her head at him, her body language screaming alert and unsure.

"Yeah, I've got it Tai." Rin leaned the bicycle against the tree. "Oi! What the hell are you doing?!"

The white haired boy immediately whipped around, holding the crossbow right at him. Tai's hackles instantly rose and she bared her teeth with a low growl, scrunching up her muzzle and crouching low with her ears pointed back. Rin barely had time to blink as he heard the whistle of the arrow being released, knowing there was something very, very sharp headed his way. A crunch filled the air as Tai leaped in front, intercepting the arrow and snapping it like a twig between her glistening teeth, saliva angrily dripping down from her growling muzzle as she glared at the brats.

"Easy, Tai. They're not worth getting yourself in trouble. I'll take care of it." Rin moved his foot in front of her front paws, glaring at the teens himself.

"Hah? What an annoying dog, shut the hell up! I'm just shooting down these shitty birds, shut up and watch!" he pointed the crossbow at the flock of birds on the ground, smirking. "Maybe I should shoot your shitty dog too."

Rin stiffened immediately, anger running through his blood and before he knew it, he had punched the snotty kid right in the face, knocking him to the ground and into the fence.

"Why you…!" one of his other friends threw a punch at him but Rin dodged easily, kicking him in the gut, but didn't see the second friend's fist from the side, feeling his head being flung back from the sudden hit. Warm blood trickled down his nose but he took no notice and knocked the crony to the ground with a hard punch.

"What is he, a demon?!" his injured friends ran to the white haired ringleader, pulling him up.

"You've gotta be kidding me!"

"Let's go!" they stumbled away pathetically and Rin scoffed, wiping his nose clear of the running blood with the back of his hand.

"Demon? Who are you talking about? You're more demonic than I am," he glanced at his hand, catching sight of the all too familiar red blood on his knuckles. "Ah ah, I did it again."

A warm lick to his other hand caught his attention, and Tai whined, this time in concern and with a slight expression of distaste, as if she were calling him a hypocrite for losing it at them after scolding her. He pulled his hand away, glaring at her.

"Shut up. You are pretty noisy," he sulked, letting his arm drop to his side. "Just what am I doing?"

She ducked her head and looked up apologetically with quite literally, puppy dog eyes, padding over to lick his injured knuckles free from blood and cleaning the injury. "Stop it! H-hey, fine, I get it! Haha, stop, it tickles! Alright!" he pulled his hand back, smooshing her head down with it.

It was always like this since he was small, he would get into fights, and Tai had always been there to help him, lick his wounds and defend him when no one else would. Dog really did seem to be man's best friend. That dog was his companion, and no one was allowed to threaten his friend. He would take down anyone who tried, and it was the same for her, as she had demonstrated before countless times. Unfortunately, this meant that they were both regularly scolded by the old man, and Yukio most of the time too.

"C'mon, let's go home."

"You lost little lamb, confess your sins and say your prayers."

"I didn't do anything bad!" Rin grumbled, resting his face against his palm.

"Then what's with those wounds?"

"I fell on the stairs."

"Your back is dirty too."

"It was quite a fall."

"What about that nosebleed?"

"I fell onto an insanely hot babe-"

"What?! After her, Rin! Lead the way!" the reverend dashed out of the confessional, all fired up and glancing around wildly. Tai yawned from her resting place beside the confessional, wincing a little as she did so and leaned her head on her paws. This was everyday to her. The reverend had white hair, and a white goatee, sporting round yellow tinted glasses that were hung on a beaded string and bounced around as he turned. He was known as Shirou Fujimoto, Rin and Yukio's adoptive father.

"Liar!" he dashed over and put Rin in a fierce head lock. "You had a fight again, right? Why do you always do this?"

"Let go, stupid old fart!" Rin cried, struggling out of the iron hold to collapse on the floor beside Tai, who looked sympathetic but a little smug at not being told off.

Stupid dog, aren't you supposed to help me out?

"They called from your part-time job earlier. They said that they don't need someone who doesn't come back after completing a delivery," he crossed his arms disapprovingly.

"You're saying that as if someone like me could do a decent job to begin with." Rin pouted, sulking a little.

"Don't act like a spoiled brat! One day you'll have to leave this abbey and make your own living! It's my duty as your guardian to make you ready for that! Or will you become a priest and lead the abbey?"

"Who'd want this rotting old church?"

"Father!" the similarly featured boy to Rin, if not for the glasses and three moles on his face, walked in smiling. "I'm finished with the preparations for moving. Now I only have to actually move the stuff."

"Good job," Shirou smiled lightly.

"Welcome back, nii-san."

Tai got up and walked over, tail swinging from side to side softly, eagerly looking up at the teen, earning a pat and a smile.

"Hello, Tai. Did you drag Rin into trouble again?" he gently joked and Tai barked playfully, wincing again as she closed her maw, and Yukio's quick eyes caught it.

"Yeah, she did." Rin hmphed, seeming to sulk more as Yukio bent down to talk to the dog.

"Or was it the other way around?" Yukio smiled straight at the dog but the words pinpointed Rin, who twitched.

"Shut up!" he bit out grouchily.

"Even though they're twins, they're totally different." One of the two priests cleaning the windowsills spoke up. Rin's spirits dropped, it was this same old comparison, every single time…

"The younger one, Yukio, is an athletic genius with amazing grades. This spring he easily got into the True Cross Academy High School division." The priest spoke admiringly.

"While the older one only causes trouble with his dog," The other priest said not without a joking tone.

"Hey, Rin, if only you had just a fraction of your little brother's virtues-"

"Shut…" Rin couldn't quite control the bubbling anger and whipped back. "…the fuck up!"

Blue flames suddenly erupted from the heater, making everyone flinch and the dog jumped back from the loud noise, looking as shocked as a dog could look.

"Whoa…I really need to buy a new heater…" Shirou ran to the heater, seemingly the only one unaffected.

"Revered Fujimoto, you have a guest." A priest informed Shirou.

"Clean up this mess before the service!" Shirou ordered, glancing at Yukio. "Yukio, treat your brother's wounds and…" he waved vaguely but caught Yukio's eyes, who nodded.

"Sure. Let's go, nii-san, Tai."

"It hurts!" Rin cried, holding his hand out for Yukio to treat. "Ouch ouch ouch ouch!"

Tai watched on restlessly, letting out a sympathetic whine now and again.

"Try to bear with it just a little longer," Yukio said calmly as he skilfully applied the bandages to the injured hand, his experienced hands moving fast.

Rin glanced at the boxes stacked in the room. "Ah, so you're moving to a dorm?"

"Yeah, school starts next week. After fifteen years, it's time to leave this abbey." Yukio smiled fondly. Tai whined a little sadly at this comment, nudging his knee with her nose.

"There there, it won't be that bad."

"So this is the last time you'll treat my wounds?" Rin smiled a little sadly. Yukio cut the bandages, smoothing it over.

"If I become a doctor, I'll help you anytime. If you pay the fees, that is."

"Your dream is to become a doctor right? Keep up the good work, I'm sure you can do it!" Rin grinned and admired his brother's handiwork.

"Don't forget about the fees, nii-san." Yukio reminded. "But will you be alright without me around?"

"What? Are you going to scold me too?"

"I'm just worried, and not just me. Father and the others from the abbey too, not to mention Taiyoume…even though she's your partner in crime. You have fights everyday and you drop out from your jobs after a short while,"

"I'm worried about it too. I know I should be growing up already, but…I really wasn't trying to pick a fight, but they were…" Rin gestured. "They were doing some nasty stuff, and then he insulted Tai, I couldn't-"

Tai barked, looking imploringly at Yukio to help defend his case. Yukio sighed, perking up a little.

"It might be a test."

"From who?"

"God!"

"You're becoming more and more like the old man…"

"Oh, here he is!" A voice came from outside and Yukio glanced at Tai.

"Nii-san, why don't you go out and see what they want?" Yukio suggested.

"Eh? Why can't they just-"

"Just go, I still need to pack up." Yukio said with a smile but an ordering tone.

"I-I get it, what are you worked up about, geez…" Rin sauntered out to meet the priests and Yukio closed the door and turned to Tai, who looked away innocently with the clueless expression, seemingly fixated by something out the window.

"Tai." Yukio slowly called. The dog twitched, still looking away obstinately. "Taiyou." No reaction, except a little quiver. "T—aiyoume onee-san."

She whipped around and whined a little and fidgeted around on all fours. Finally, she spun around in a full circle like she was trying to catch her tail, doing a full body shake before retreating behind into one of the side rooms. After a moment of silence, loud cracking noises and stifled yelps floated out from the room, and even though Yukio had heard it countless times, he couldn't help but cringe a little.

"The clothes are in there like usual, Taiyoume onee-san," he called out, pulling tweezers and cotton from his first-aid kit.

"Yeah, I see it…thank you." A slightly croaky female voice called out, as if from misuse and unfamiliarity. "I told you to definitely not to call me that, Yuki." She cleared her throat and a lighter, smooth voice came out, not soft, but with a hint of shyness that came from being called his name for her when they were younger. She had a slightly deeper voice than most girls, not so much manly as verging on a continued howl that formed words. What he called her, she knew it was a ploy to get her to change into a human, but it worked every time.

"Otherwise you wouldn't listen, Tai." Yukio smiled at her, an 'average' 16 year old girl, as she walked out from the room, wearing the baggy blue jacket she always did and the matching cap that was slightly more airy at the top. She wore a loose black t-shirt inside that Yukio knew she had to otherwise she couldn't hide her black tail, and slack jean shorts that went to her knees to accommodate for the tail space at the back. The cap was to hide her black ears, though she never told him where she got it from, it had just been with her from the start, along with the jacket. The first time they met seemed like light years away.

Unfortunately, even with those incriminating features hidden away, Tai had the misfortune of having shoulder length white hair that stood out against the black, which she was now tying up into a ponytail she could fit through the back of the cap, which could eventually be obscured by pulling the large hood over both hair and cap to only leave the cover of the cap showing. The front hid her dagger like yellow eyes the best it could, and on days where worse came to worst, she had to wear contacts.

Yukio hadn't noticed before, but since it had been a long time since her last transformation back into a person, he really noticed how she had grown. She was taller, and looked less like a child, although her baggy clothes hid her curves well. Her face hadn't changed much, still very much sweet when she smiled and adoring expression, but also with a hint of danger and deadliness he had seen firsthand, from the sharp glinting eyes and nose, which he knew was very sensitive and could detect a range of smells even in this form.

The conclusion they had reached for her white hair it was most likely from the stress that 'changing' took on her 'human' body, but since she was a black wolf, the transformation back into the wolf changed the pigment in the hair colour back to black as it altered the very DNA and structure of her body. Yukio vaguely remembered that her hair hadn't always been white, when they were younger, her hair had been a darker shade, leaning towards black and more a grey. As they grew older, it slowly lightened and had now reached a startling white, verging on silver. But everything about her was a 'conclusion', there wasn't much they knew about her, nothing concrete, except for the fact that she was definitely not human, could change into a wolf-or something that resembled that- was some sort of demon and would protect Rin with her life.

AN: Sorry nothing much happened here, but I just wanted a description and intro down. Uh, also, her name 'Taiyoume' means 'sun eyes', you'll learn more about that later :D I know, another one of these wolf/dog to human changes with the ears and tail on the girl, but I think it's a little different, so give it a chance :) You might like it. If you did, please leave a review so I know if I should continue it, or maybe just give me some feedback or encouragement, that's always fantastical (as in I will dance around the room and kick things over) Thanks for reading!