Another patrol, another night without a hitch, Yuki thought as she entered the Headmaster's bathroom. She was exhausted as she leaned against the door after closing it. That was normal, as a guardian she was required to stay up all night. And she didn't mean to like three in the morning, she meant like now when the sun was starting to come up.

That made it a painful schedule. Start the shift at dusk, and then patrol for the remainder of the night. At dawn, shower and get ready for class. And more than likely suffer make-up classes afterwards. Repeat the process five days a week and there you have it, a helluva job to do.

Yuki would never complain though, since it was not just because she accepted it. She had a duty to do. You see, Cross Academy wasn't just a school. No, it held a dark secret.

There are two classes in the Academy: the Day Class and the Night Class. The Day Class uses the school during the day, and leaves to return to their dorms so the Night Class could use the building.

What no one in the Day Class knows is that the Night Class is made entirely of vampires.

That was what Yuki, as a guardian of the school, had to protect. Should anyone in the Day Class or any of the teachers know of it, all hell would break loose and the peace that the school represented would be destroyed.

"And then, the whole concept of humans coexisting with vampires would be just that, a concept. One that will never be a reality," Yuki said, placing her towel and shower things on the edge of the bathroom sink. She took a long look in the mirror, looking into the girl with reddish-brown eyes staring back at her, and noticing the wrapping around her neck, covering her own dark secret. She then got out of her uniform and into her pre-dawn clothes, a simple shirt and school skirt.

She didn't even notice the door open, and it wasn't until he walked behind her that Yuki finally snapped out of it.

"What the hell are you doing in here!"

Zero looked at her with a disinterested face, "The bathroom in the boys dorm is out of service, so this is the only one left."

"You could have knocked first!" Jerk!

Zero Kiryu, the other guardian of the school, Yuki's friend, and her partner. He was also a Day Class student, and also lived with the Headmaster as his 'son' (a term everyone used rarely, Zero had a short fuse). He wasn't the nicest guy in the academy, but Zero wasn't exactly the meanest either. He had a short fuse, but he was also had a soft side. Though he rarely ever showed that side of his personality.

"Besides, you should have put the sign out on the door to let others know it is in use," he said, setting his things on the opposite corner of the sink.

"Very funny. Anyway, you notice the door is painted differently? Its red now." Yuki said, just to try and start a conversation with Zero.

Normally he wasn't very talkative, but this time Zero seemed to be less grouchy, "I did. How stupid."

Yuki sighed, "Stupid because of what color it is, or what it could mean?"

"..I wouldn't know what the Headmaster has going on in that head of his," Zero said, leaning over the sink. "How's your wound?"

"Oh? You mean the small fall I had? It was nothing. Just a scratch," Yuki quickly replied, looking at her hands, which had small scrapes on them and a big one on each of her palms. She had only fallen a few feet down some stairs, but the angle she fell to ensured that she would get hurt nonetheless.

Looking at her right palm, Yuki noticed little red slivers on her skin. As she closed her hand, she saw Zero shift a little away from her.

Does even a tiny amount disturb him?

"Zero…when was the last time you had any…?"

He didn't answer, instead walking away towards the door. Yuki shut the door as soon as he opened it by a crack. "Zero."

He sighed, "You're pushing me into answering a question you already know the answer to."

I knew it, not since two days ago. "You'll start to go into a frenzy unless you have—"

He cut Yuki off, grabbing her by the shoulders, "Will you never stop giving yourself to me? Do you have to insist on lending yourself to me?"

Yuki's hands were on his, looking into his eyes, a light red, "Zero. You know very well where I stand on this."

"I'm a vampire…a monster, a creature that feeds on human blood to live on…you should just kill me," Zero replied, nearly hissing at Yuki.

Zero was a vampire, like he said. Not a pureblood, but a vampire nonetheless. It had been only a few weeks ago that his secret was revealed to Yuki, a secret she had no idea had existed. Her 'father' had known about it, but kept it hidden from her for nearly four years. Supposedly it was for her safety, but Zero had been her friend, weren't friends supposed to share secrets?

But there was a secret she shared with him, one she would never tell anyone, not even Kaname Kuran. "And I'm the one you take blood from, so you won't hurt anyone, Zero."

That was why Yuki wore the gauze around her neck, to hide the evidence of her crime. Giving blood willingly to a vampire was a forbidden act, especially between a vampire and a human. What Yuki had been doing with Zero for the past few weeks was viewed as blasphemous among humans.

But she didn't care. She welcomed it.

"And you're a fool," Zero replied. He didn't like the idea of feeding off Yuki, and he was not shy of telling her that.

"A fool I may be, but you're an even bigger idiot if you don't take me when you have to," she retorted.

Zero couldn't reply to that in a sarcastic way. There was no getting around Yuki's stubbornness, she would never budge. And she was right. If Zero didn't feed on her, he'd more than likely go after a Day Class student and his secret would be out.

Zero silently conceded defeat, moving to have his back against the door. The dark-red door. The color of blood.

Yuki couldn't help but notice the coincidence, and she followed Zero down to the floor, where he was sitting, looking off with his eyes looking at the shower stall across the room. She was between his legs, and before she could react, Zero had already grabbed her, putting a hand on her back, and his other hand began to remove the gauze around her neck. It revealed the deep fang puncture wounds from his last visit with Yuki.

And the girl could feel Zero's breath against her skin, warm for exhaling and then cool for inhaling. Each moment that he hesitated, Yuki could swear she could hear her heart beating louder until she was sure she could feel it about to explode from her chest. "Zero…"

"You realize what you do to me…" he replied, licking her skin where her wounds were.

I do, Zero, but I would not have it any other way…if I can give what you need, I do so willingly.

Her thought was gone the moment he bit her skin. Yuki kept her breath in, and let it out the split-second after he had punctured her skin. The bite was worse than last time, and she leaned back in an involuntarily effort to get away, but she fought against her natural instincts. She was doing this for Zero, and she would not try to get away unless he filled himself…or she had to resort to that.

The sound of him sucking her blood out of her body remained the same no matter how many times the had done this. A sickening sound that made her blood cringe, even as it left her body.

Yuki found herself leaning back far enough to where she was looking right up at the ceiling and tears were forming in her eyes. Not out of what she was doing, or the pain that was flowing through her, but because she knew what she was doing was for Zero. He may have resisted the urge, but she was forcing him to feed on her, against his will. This was painful for him, and that was what she regretted the most.

But…he has no choice… Yuki thought as she felt her back touch the cold hard tiled floor. Zero had followed her as she had leaned back. He now hovered over her, still drinking from her neck, and his hands had moved to secure her hands on either side of her body against the floor. Yuki's face was a deep red, noticing her position, but she couldn't find it in herself to protest. Zero was not done with her yet, and she was willing to let him have as much as he needed.

Even if he drained her dry…

Seconds later, Zero's lips left her skin. Heat from the wound on her neck was pulsing, and while Yuki felt slightly dizzy, she was still conscious at least. Covered in perspiration and sweat, Yuki sat up slightly as Zero kept a hold of her shoulders, "Zero…?"

Was he finished?

As she felt blood trail down her neck and along her chest, Yuki ran a hand through Zero's silver hair, "What's wrong…?"

Zero lowered her back to the tiled floor, "I —"

-Yuki gasped when Zero ripped her shirt open, her face turning ever redder—

And yet, as odd as it seemed, Yuki did not try to stop him as he licked up the blood from her wound. Her mind told her to at least chastise him, but her words were unable to escape her mouth. The feeling of Zero's tongue against her neck, then to her collarbone tracing it to the center. Yuki's right hand was still in Zero's hair, her grip tightening slightly as he went lower.

Yuki's left hand went down her side to her thigh, where she had a small pistol holstered there. Zero had given the pistol to her, so she would kill him if he went to Level E…or tried to kill a human. She had carried it with her ever since then, and swore to use it as a last resort. She made that promise to Zero, she hoped she wouldn't have to fulfill it. She had been hesitant to accept that responsibility.

He began lapping up whatever blood he could see, as if he was trying to hide evidence to a heinous crime, and he stopped once Yuki inhaled sharply, lifting his head to look her in the eyes, "I'm sorry—"

Yuki sat up, positioning herself on Zero's lap, "For what?" She saw his eyes, turning the brightest red she had ever seen them, and blood dripping from his chin, dripping onto his chest. His fangs, seen protruding from his mouth, were coated with the crimson liquid that had once been her blood, but was now his sustenance.

"Despicable…taking advantage of you," Zero replied, his right hand going to Yuki's cheek and his left going to her left thigh. Normally, Yuki's Artemis Rod would be holstered there, but she had removed it prior to Zero's entry. So, all that greeted his ice-cold high was the bare skin of her thigh, sending a shiver up her back.

But Yuki didn't mind it, "Zero. It's alright…"

His shock was apparent in his eyes, "Lusting for flesh and blood…that's what vampires do, right? If so, I'm used to it by now…" Somewhat, she admitted. If it was Zero, she would allow it. "There is something you want, go ahead and take it. Take me, if you want to."

Her lack of hesitation stunned him, and Zero remained silent for a few seconds before he leaned in to whisper in her ear, "Whatever happens here, stays here. Got that?"

Yuki nodded, "As does everything else we know, Zero…"

Zero's lips returned to the girl's neck, and Yuki gave in willingly to her friend.

Yuki returned to school the following day, bright and cheerful as always, as did Zero, still being his usual cold self. But something between them happened that night. What happened in that room remained a secret to their dying days. What secrets were shared behind the crimson door shall remain what they are. Secrets, secrets that nobody would ever know.