Title: The Kakuja Effect: Prologue

Chapter: 1/?

Info: This story starts around the True Cross Academy Festival arc. In this AU Shima is not a spy. This story was inspired by Tokyo Ghoul, in which there are ghouls (ghouls are similar to demons), who mutate through repeated canibalization.

Disclaimer: I don't own Ao no Exocrist/ Blue Exorcist or any of it's characters.

The changes in Rin were subtle at first. By the time he noticed something was wrong, it was already too late.

First, his sense of smell changed. The smell of freshly cooked Sukiyaki, his favorite meal, instantly made him nauseous. It appealed to him as much as fish intestines that had been left out in the hot sun to rot.

After his sense of smell changed, his sense of taste followed soon after. Regardless of what he ate, or what he cooked, everything he ate tasted like it was on the verge of spoiling. Even just looking at food made him feel sick to his stomach.

Thirdly, and in his own opinion, the most bizarre thing to change was his attraction to people. Not in the romantic sense, but the alluring smell of them. To him, they smelled sweet like freshly baked sticky buns.

Forth was his constant and insatiable hunger that kept him awake at night. His hunger was constantly in the front of his mind, but no matter what he ate, it left him feeling sick and sequentially would lead to him vomiting the contents of his stomach. The painful ache of his empty stomach was getting worse by the hour.

Yukio left the dorm room earlier that morning, he mentioned something about a low-level demon that was running amok and causing the order some trouble. Yukio glanced over at his older brother and realized that he was still sound asleep. He left the room without another word.

'Some things never change.' Yukio thought as he left the room.

Rin waited, completely still and quiet for the door to close. When he heard the sound of the latch click shut, he unintentionally let out a small whimper. He hadn't been sleeping at all. The sweet taste of his blood coated his lips and tongue, to keep quiet, he had bitten down on his hand to keep himself from crying out and alerting Yukio.

Warm tears ran down his face, God, he was so hungry. What the hell was going on with him? Everything he tried to eat made him feel sick. He raked a hand anxiously through his hair, he had no idea what was going on.

"Please stop..." He cried, "Someone please, help..." But Rin was sat completely alone in his room, leaving no one to hear his cried for help.

'Yukio, he would know what to do, right?' Rin thought desperately, 'No! Don't cause him any more trouble! You've caused him enough problems as it is.'

Shakily, he pushed himself into a seated position and pulled his knees tightly to his chest. He rested his head on his knees and sat there for a long while. Reading the clock on the desk, a bolt of shock jolted through him. An hour had already passes since Yukio had left, even though it felt like he was just there moments ago.

Gripping the desk to stabilize himself, he slowly stood up. Malnutrition from a lack of nutrients made his legs shake with fatigue. He stood there for a moment and tried to pull himself together. He couldn't let anyone know. He couldn't look weak in front of them. They would call him pathetic.

Deep down, Rin knew that wasn't true. His friends would stand by his side and help him, but his twisted, ravenous thoughts told him other wise, coaxing him into believing that this was all his fault.

"Just make it through today." Rin begged himself.

-~x~-

Yukio was a patience person by nature, especially when it came to Rin. But sometimes Rin really liked to put his patience to the limit. Yukio had waited an extra five minutes to start his class. Then ten. And then fifteen. It became clear that Rin had every intention on missing class, and absolutely no intentions on joining his classmates for class. Even Yukio couldn't stop the world for his brother.

Yukio rubbed at his temples, fending off the impending headache that was building behind his eyes. It would take a little more than a tardy student, brother or not, to break his composure.

Yukio let out a long sigh before apologizing to the exwires, and started his lecture on how to properly clean Naberious inflicted wounds and how to stop them from becoming infected.

He was part way through handing out a list of purifying herbs that we commonly used to help reduce the swelling of Naberious wounds when the classroom door creaked open.

Without looking up from what he was doing, he simply said, "Rin, take a seat next by Miss Moriyama. Shiemi, could you please fill him in on what we just went over-" He looked up at his older brother and froze.

Rin was a complete mess. Aside from being utterly disheveled, his eyes, red and swollen as though he had spent the last hour crying. His eyes, normally so full of joy, were void of their fiery passion. He had a fake smile plastered on to his face, and waved at the class.

"Sorry I'm late!" He said with forced cheeriness, "It won't happen again."

Before Yukio could collect his thoughts, Rin shuffled over to his desk and slumped into the chair. tossing his bag half-heartedly on the ground. The whole classroom had gone silent.

Yukio walked over and leaned towards his brother, just out of earshot of the others and whispered, "Nii-san, what's wrong?"

"Nothing." Rin replied too quickly, and then added, "Nothing. I promise."

Rin avoided making eye contact with Yukio.

Yukio gave him a pointed look, his face was full of concern.

"R-right, as I was saying..."

He handed Rin a list of the herbs they were going over and continued his lecture.

He spared a glance at his brother, Shiemi was trying to explain to Rin what he had missed out on, but Rin looked vacantly ahead of him. Clearly lost in another world. Only nodding and asking 'Really?' when Shiemi paused.

Yukio's eyes wandered around the classroom and he caught Bon's eyes, his troubled expression mirrored his own.

Something was wrong.

At the end of class Yukio grabbed his brothers elbow and pulled him to the side.

"Rin, what's going on? Is everything okay?" He asked, his face full of worry.

"It's nothing." Rin replied easily.

Yukio sensed the lie. "Are you sur-"

"It's nothing" he hissed back at Yukio. Rin wrenched his elbow from Yukio's hand and walked swiftly from the classroom.

Yukio stood there, stunned. His mind working at one hundred miles a minute trying to understand what just happened. He would have to ask him later tonight at the dorm room, where they could talk in private.

The only issue was that Rin didn't return to the dormitory that night.

And he didn't return for two more years.