This is my first Kingdom Hearts fanfic. I don't own Kingdom Hearts, but if I did, Sora would totally be all mine...haha. Story is mostly original, but it is inspired by Vampire Knight. I hope that you guys enjoy. Reviews and criticism would be appreciated.

NOTE: The first section of every chapter is usually told from Kairi's POV, whereas the rest is in the third person. "Stained by Sin" is only the working title. Hopefully something better will come to me.

Summery: Sora disappeared from Kairi's life for unknown reasons. Vampires bring them together again, but it also tears them apart. Blood, lust, fear, secrets, friendships, reunions, and promises change their lives.


1. SCENT OF DISCOVERY
~Kanashimi no Kizu~

I ran up that steep hill, my breathing getting heavier and more labored as I approached the peak. I had to see him at least once before he disappeared from my life. I had to let him know how I felt, that I loved him. At the top, a dark shadow stood beside the old oak tree against the bright setting sun. Reds and oranges, the color of twilight, bathed his figure.

"Sora?" I called as I neared the tall tree, "Is that you?"

The dark figure only nodded as a response, remaining silent as he walked toward me.

"Why didn't you tell me?" I pleaded, finding my breath. "Why are you leaving?"

Sora stepped in front of me, his bright blue eyes intently gazing into mine. By looking into them, I could tell he wasn't going to answer me. He took my hand into his, holding it tightly, like he was afraid of something. His fingers trembled as they held on tightly to mine.

"Sora, before you go, I wanted to tell you…" My breathing was becoming more fast-paced from nervousness. "I want to tell you how I felt, that I lo—"

I never got a chance to finish. Sora grabbed my waist, pulling me toward him. He pressed his lips against mine, slipping a piece of paper in my hand. After an intense moment of passionate kissing, he broke away abruptly, the sensation of his lips on mine still lingering. He leaned toward me, whispering his last words in my ear.

"Wait for me…"

Before allowing me to respond or say goodbye, Sora disappeared as a dark figure into the sunset. I touched my lips, the warmth from his lips still there, and then remembered the note he slid into my fingers. Leaning against the tree, I delicately unfolded the piece of paper.

"There's something that I need to tell you, but now is
not the right time. I'll come back to you when the time
is right. So please, just wait for me."

-----

"Kairi! Are you even listening to me?"

Quickly re-folding the note and tucking it safely in her sleeve, Kairi looked up at her boss…who was also her father.

Her father was also a researcher. Professor Kaito studied a very strange topic…the topic of vampires. He worked to find a substitution for blood to satisfy a vampire's thirst for it, the only major difference between them and normal humans. On top of being a father and a scientist, he ran an agency where a select trained few hunted Renegades, rouge vampires whose blood-thirsty nature had completely taken over.

"Honestly, Kairi," her father scolded, "if it weren't for the fact that Riku was your partner, you'd be gone out there."

"Sorry dad," she apologized, "won't happen again. I promise."

"I don't know whether to believe you now or the first fifty times you said that," her father retorted, handing Riku, who was sitting beside Kairi, a manila envelope. "There have been many reports about groups of people being found unconscious in an alley in the downtown area of the city. The people are fine, but have strange markings on their necks. I want you two to go check on this, but be careful," he urged, "you two have school tomorrow."

"Nice to know that you care about our well-being," Riku joked, leaning back on his chair.

"Your school's been on my case because of how often you two sleep in class or call off because of injuries," he explained. "Since they can't know the complete truth, I have to take some of the blame…actually most of the blame."

"We got it, we got it," Riku said before Kaito started off on some rant. "Is there anything else?"

"Nah, you're dismissed," he answered as the two started to leave. "But, Kairi, honey, be careful."

Dad, I'm not a little kid anymore," she responded. "I'm seventeen now. Don't treat me like a child."

"Are you sure you want to do this?"

"Yes, I'm positive about this."

"Just…be careful," he answered after a moment of brief silence, as if he wanted to tell her something, but opted against it.

"I'll try," she replied, following Riku, who carried the manila envelope in his hands, down the hallway.

"Why do you keep pulling out that silly piece of paper?" Riku questioned.

"It's not silly!" she retorted, clutching the note to her heart. "It's the last thing he left me before he left a year ago."

"Is he the reason you're doing this?" he replied. "Putting yourself in danger by going out and hunting vampires?"

"I'm not exactly sure he's the reason, but something inside me tells me that if I do this, I'll get a chance to meet him again."

"Yeah, in a dark alley where you find out that he's become a bloodthirsty beast bent on sucking the blood out of your neck."

"Don't even joke like that Riku! He was your friend too," Kairi responded, finding it hard to believe that Riku would even joke like that. "Besides, why are you doing this? Vampire suck the blood out of someone you know?"

"Actually," his tone had become dark and serious, "yes. Just last year. A Renegade attacked one of my friends from across the state. I promised to find a way to avenge his death, along with all the others who fell victim to vampires."

'I'm sorry," her voice dropping to an apologetic tone, "I didn't know."

"It's okay," he told her. "I never told you."

The air between the two of them became quiet as they geared up. Kairi picked up a long silver rod, named Flowering Strength, and collapsed it to the size of a water bottle, placing it in the band wrapped around her right leg. Riku loaded his silver gun, Way to Dawn, with anti-vampire bullets, an invention by Kairi's father that would only harm the sorrowful creature of the night. He put away his weapon into the protector located at his right hip. They both went outside, Riku handing Kairi the envelope as the two stepped into his car.

"Your dad did say that we were going downtown, right?" he asked, starting up the car.

"Yeah," she answered, reading the documents that she pulled out from the envelope. "By that abandoned apartment building across the street from the tattoo parlor."

"One of them could've done it," he said, giving the gas a bit more pressure. "Maybe they thought that it would've been a hilarious prank to make people think vampires exist."

"But then why wouldn't they just make the marks look more like a vampire bite?" Kairi argued. "Only a few people can distinguish the mark of a vampire. Otherwise, it looks like a strange marking to normal people.

"You're right about that," Riku agreed, turning onto their desired street. "Looks like nothin's going on tonight."

"Wait, wait," Kairi put her hand up, "I think I saw something."

"How can you see anything? It's pitch black out there except for the light of the moon."

"If you're not coming, I'll go by myself." She opened the door and quickly stepped out into the brisk cold air.

Riku followed, locking the car door from the inside so to not make too much noise. "What did you see?"

"Something…or someone staggering in the shadows," she explained, pointing to the alley. "And I think something was following it."

"You think it's what we're looking for?"

"Dunno, but we should check it out."

Slowly and in pace with each other, Kairi and Riku started toward the alley. It was silent, that walk down the alleyway. Then the sound of something - more like someone - being thrown against the brick walls resonated into the dark sky, followed by grunts of pain. The pair rushed down the ominous path. When they arrived at the origin of the cries, a tall man clutched a young teenager by his throat, the first barring his fangs and ready for a meal.

Kairi gasped when she saw the face of the young man in the sickly pale moonlight. "I-i-it can't be…" she muttered.

The vampire, upon hearing her voice, turned his attention toward Kairi, a gluttonous gleam in his eyes. "A girl…" he said lustfully, "…and a pretty one at that…I wonder how she would taste…"

"You take one step toward her," Riku threatened, his Way to Dawn in hand and loaded, "and it'll be the end of you."

"At least let me enjoy one last meal," the man replied, pushing the boy up higher against the black curtain of concrete and drawing his fangs closer to the young boy's neck.

Kairi acted quickly and grabbed Flowering Strength, holding it against the vampire's throat. "Let go of him," she commanded, her eyes serious, "now."

The man was wincing from the effects of the staff. "How about you take his place?" he asked. After he didn't receive a response, he questioned, "No?"

Stealthily, the man slid his foot underneath Kairi, and the next thing she knew, she was laying on the ground, her head pained from connecting with the ground. With an open opportunity, the vampire fled under the cover of the darkness of the night. Gunshots were heard, but none hit their target. Riku hurried to Kairi's side.

"You okay?" he asked, putting his gun away as he kneeled on the ground next to her.

"Don't worry about me," she answered, sitting up with certain difficulty.

"Are you nuts? You could've gotten a concussion from a hit like that," he replied, watching her getting up on her feet. "What are you doing?"

"Sora…" she said, walking with some complication. "We need to make sure…" her breathing was getting labored as her vision started to blur, "make sure…that Sora's okay…" She collapsed onto the ground and everything went black.

------

"Kairi? Are you okay?" a voice called out as Kairi slowly regained consciousness. Two blurred figures came into view as she opened her eyes.

"Riku?" she said, finally awakened only to find herself sitting amongst a pile of trash bags. "What am I doing here?"

"Looks like you really may have suffered something from that first fall," Riku diagnosed, relieved that she was okay.

"Who is standing behind you?" she asked, seeing a figure cloaked in darkness move in the space behind Riku.

"C'mon Kairi," a familiar voice answered, stepping froth into the dim moonlight, "it's only been a year. You already forgot about me?"

It took Kairi a moment to realize that the voice belonged to the person she was waiting for. She could hardly contain her excitement and threw her arms around him when he stepped in front of her. "Sora! It's really you! You've come back!"

"Yeah," Sora replied, slowly putting his arms on her back, "I'm back."

Tears filling her eyes, Kairi held him tighter, but that caused Sora to let out a small groan of pain. At that point, Kairi felt some kind of liquid soak into the sleeve of her jacket.

"Sora, you're bleeding!" she exclaimed when she realized the liquid was trickling from his neck. "You didn't get bitten, did you?"

Sora reached up and touched the wound. "No," he responded in a flat voice after looking at the blood on his fingers and quickly wiping it on his pants. "His fingernails must've cut me," he concluded, referring to the vampire.

"We should get that bandaged," Riku stated, tearing off a piece of his shirt and handing it to Kairi. "We'll have to do that at the clinic, so this will have to do for now."

"Thanks," Sora answered as Kairi wrapped the fabric snuggly around his neck. "I really don't like the scent of blood."

"Does it make you queasy?" Kairi asked, finishing the knot of the temporary bandage.

"Not exactly," he replied, touching the site of the wound again.

"We should probably get going," Riku suggested, already heading back to the car. "Your dad's gonna wanna run a medical check on Sora."

Kairi took Sora's arm in hers, urging him to come with her. "Let's go, Sora. My daddy's probably gonna run that medical check. Besides, he'll be so happy to see you."

Sora followed, but with full knowledge that 'daddy' wouldn't be so thrilled to see him. That was unless he had a certain piece of information that the professor wanted to hear.

-----

"Your father's busy right now," someone informed Kairi when she asked to see her father. "He's putting together his research on the blood tablets to present to the government, but he'll meet you in his office in about five minutes."

"Thank you," Kairi responded as the woman walked away. "I guess that we'll have to go to daddy's office and wait."

"I think that you need to be checked over too, Kairi," Riku stated.

"I'm fine," she argued.

"I agree with Riku," Sora said. "I don't want you to be seriously hurt because you tried to help me."

"Fine," she relented, being outnumbered 2-to-1. "But at least let me go with you two to daddy's office. I promise to go get my head checked when we get there."

"But Kai—"

"Sora," Riku interrupted, "you've been gone for a year and obviously don't remember how stubborn she is."

Smiling at her triumph, Kairi linked arms with her two friends. "Let's go."

Along the way to the back of the building, Kairi pointed out the various rooms and what research was occurring in each room: one was developing anit-vampire weaponry, another was dedicated to research on the blood tablets, and another was specialized in studying the swift healing ability that vampires possessed.

Someone walked out of a room marked "Product Testing" and saw the group, doing a double-take when he saw the third person with the usual two. A look of recognition appeared on his face and he rushed over to the three.

"Hey Axel-sama," Kairi greeted when he approached them.

Completely ignoring her, Axel took Sora's free hand in his, shaking it with fierceness. "Sora! I can't believe it's you. You're alive!"

"You two know each other?" Riku asked, making certain unseen observations and connections in his mind. "How?"

"I'm sorry, but I don't know him," Sora answered, nervous about something as he pulled his hand way from the stranger's grip.

"Well, he seems to know you," Riku stated. "That's a little strange, considering that you're human and Axel is one of our resident vampires."

"You've got vampires living here?" Sora inquired.

"Yeah, some of them even come to school with us," Kairi responded. "So Axel," she shifted the conversation to another topic, "how are the blood tablets?"

"I've had better," Axel joked. "It really doesn't substitute for the original just yet. Although they're better than the first batch."

"I just want to thank you for convincing the other's to help our research," Kairi said.

"Well, as a Superior, I do have some powers over the others," Axel replied. "Besides, if it helps to decrease the number of us getting hunted down and killed, I want to provide any help possible."

"Well, thanks Axel-sama. We've got to get going, so I'll see you around."

"Now if only they would just let me bite just one neck…" Axel mumbled to himself as he walked away.

"Should we worry about him?" Riku asked as they proceed to the door at the end of the hallway.

"Nah," Kairi answered, "he's always been sarcastic, ever since I met him a few years ago when daddy asked for his help in his research."

"That really wasn't what I was talking about," Riku replied, watching over Sora carefully as Kairi unlocked the office door.

"Then what were you talking about?" she asked, opening the door and turning on the lights.

The room was white, like a normal doctor's office. The only strange thing about the room was the map of the city on the wall behind the desk with large X's on it to mark areas with large amounts of rouge vampire activity. The bright lights reflecting off the wall caused Sora to blink a few times.

"Never mind," Riku said. "Now you go and get checked like you promised."

"Okay, okay," Kairi answered. "I'll meet you at your house tomorrow before school, Riku," she turned to Sora, "Good night Sora."

"Night Kairi," Sora replied as she closed the door.

A strange silence fell over the two friends remaining in the room.

"So," Riku sighed, "how long do you intend to keep hiding it from her?"

"Hide what?" Sora replied, a nervous chuckle choking up in his throat.

"She'd accept you for what you became," Riku continued, unchanging at Sora's questioning.

"What are you talking about Riku? Sora responded, feeling more afraid with each passing second.

In one swift move, Riku had Sora pinned against the closest wall with one hand. "You can't fool me, Sora." He ripped at the cloth around Sora's neck to reveal what was, or in this case, what wasn't there. "Funny, I could've sworn that there was a cut here, but there's nothing now." Riku released Sora, having finally getting his point across.

"How did you know?" Sora questioned, unfazed at the fact that Riku had just attacked him.

"I suspected something when you said that you didn't like the scent of blood," he explained, keeping his distance from Sora. "But it was so obvious when Axel came up to us and recognized you even though you never met him before."

Sora looked away, clearly ashamed at being found out. "I didn't choose to become this way."

"It's a wonder Kairi didn't notice," Riku stated. "She's been studying all this ever since you left."

"You're not going to tell her, are you?" he asked, his eyes open wide in fear.

"Even if she knew," Riku explained, "she'd accept you for who you are. It won't matter to her if you've become—"

"That's the thing Riku, I don't want her to find out," Sora pleaded, falling to his knees. "I don't want her to get wrapped up in the situation. I don't want either of you to get involved…"

"Get involved in what?" Riku questioned, surprised at the fact that his best friend was crumbling to pieces in front of him.

Luckily for Sora, a knock came at the door, giving him a temporary escape from answering the question Riku imposed on him.

"Okay," Prof. Kaito declared as he walked through the door, "who is this friend my darling daughter told me about?" The professor slid the pen he was writing with behind his ear and adjusted his glasses before looking in Riku's and Sora's direction.

The wooden clipboard the professor was holding slipped from his hands, landing with a small thud as it clattered against the ground.

"What are you doing back so soon Sora?" Kaito asked. "Did you find who did it?"


What happens next? Find out in the next chapter: UNEXPLAINED RECOGNITION.

Please review! Me like reviews!