Hello, beloved readers. I am shocked, I'm actually uploading two fics in one week, aha. I wasn't actually planning on writing this one, but the idea just refused to leave me alone, so... Here you go. The idea and title of this fic came from the song by Soundholic, which I highly suggest listening to. =3 I warn you, this is probably going to be sad and dark, involving noncon and angst. I'm also going by the idea that, seeing as she /is/ human, Keine has trouble controlling her youkai instincts on the full moon. This also takes place a great deal of time before Imperishable Night - possibly a few years. It's my first time writing both of these characters, but I hope you enjoy.

Mokou hated the full moon. At one point in her life, before she ever met Kaguya, before she consumed the hourai elixir, before she came to Gensokyo, she had found it beautiful. But now the full moon represented nothing but anger and loneliness.

Ever since she'd met Keine, Mokou had been unable to stomach the full moon.

Every month, for the day leading up to until the day after the full moon, Keine would leave. Mokou tried not to questioned where she went, never tried to follow her, but she couldn't deny the fact that she was utterly hurt whenever she left. Keine was the one woman that Mokou truly loved in the world, the one person that she trusted more than anybody else. The fact that Keine didn't want her around during her most vulnerable moments hurt, like Keine couldn't trust her back.

But Mokou would never say that. She would never let Keine know about her insecurities, would never make her worry. If Keine wasn't ready to see her during those times, then it wasn't her place to push, and all she could do was spend as much time with her as she could during the days in between.

Today was one of those days. Keine had just finished teaching her class and sent the kids home for the day, a kind and gentle smile on her face as she waved goodbye. Mokou couldn't help but smile in turn as she watched, bowing her head in silent amusement as she leaned against the wall of the school building. Sometimes she doubted that Keine even had bad days, she was always so pleasant. She could certainly get serious at times, at least enough to be a good teacher, and she could get sad and embarrassed, but Mokou had never seen her actually get angry. It was refreshing, to meet such a pure person as her when she had spent so much of her life shrouded in darkness. Keine was her light; she always would be.

The school teacher turned around with a start when she heard Mokou's foot scuff the ground, a soft flush on her face as she turned around to face her. It was clear that she hadn't noticed her presence, and she smiled happily as she raised one hand in a wave.

"Mokou, good afternoon," she chimed, while the phoenix simply nodded her head in acknowledgement. She straightened out her back and stepped away from the old school building, raising her head and offering a small smirk as she headed out to join her best friend.

"Are you finished teaching for the day?" She questioned, cocking her head towards the leaving students with smiles plastered on their faces. A second look showed that a few of them were clutching small bags, and Mokou instantly knew that Keine had given them a treat today. That was right, the full moon was coming soon… That meant that she'd have to cancel classes. The history teacher nodded, then pointed towards the small house behind the school building.

"I was just about to head in for dinner. Would you like to join me?" She offered, and Mokou quickly nodded. If memory served her right, Keine would be leaving tomorrow for her monthly absence, so Mokou wanted to spend as much time with her as she could before she left, even if it was just doing things like eating together and talking.

"And so then, Kaguya got me good, haha!" Mokou's usually pale face was flushed red, a cup of sake in her hand as she sat on the floor of Keine's humble home. Her normally indifferent face had broken into a wide grin as she explained the details of her last fight with her rival. "Blasted a hole right through my gut! I thought for sure I was gonna die for real after that, but I guess it really is impossible."

Keine's lips were pulled into a tight smile as she watched her friend take another drink, slamming the empty cup down before clumsy hands reached for the bottle to pour some more. In reality, she hated these kinds of conversations. Mokou may have been immortal, but Keine hated to see her hurt. She treasured her, as a close friend and maybe, possibly as something more, and hearing her talk so casually about her injuries broke Keine's heart. It was as though Mokou didn't care about her own body. As though… As though she would let harm befall it without thinking. It was something that worried Keine, that made her feel sick to her own stomach just to think about it. She wished that Mokou would treasure herself as much as Keine did. She wished…

"Keine? Oi, Keine!" A pale finger flicked her forehead, knocking her out of her reverie. Brown eyes opened to stare into concerned red ones, and Keine realized that Mokou was leaning over her, a confused expression on her face. "I was askin' you if you were gonna drink, but you didn't answer me. Are you ok? You thinking' about something?"

Mokou looked so cute right then, with the expression of a worried child, and Keine couldn't hold back a slight giggle. The other girl quickly pouted, pulling away and crossing her arms in annoyance.

"Hmph! What's so funny? I was just worried about you…" she grumbled, the blush on her cheeks darkening as Keine chuckled once more. It was sweet how Mokou worried about her, it really was, and she didn't mean to laugh, but…

"Nothing, nothing. I'm just happy that you care, Mokou," she teased, which resulted in the blush growing even further, and then Mokou snatched up the bottle of sake, pouring out two cups. She grabbed one for herself and downed it quickly, then pushed the other towards Keine, an insistent expression on her face.

"Hmph! Don't get all sentimental on me, Keine! Come on, drink! It's no fun if you're all mopey and I'm drinking alone!" She replied, and Keine reluctantly took the cup from her hand and brought it to her lips. After one sip she began to relax. Mokou was right… Tonight was a night for having fun. There was no point in thinking of depressing things. Just drink and be happy.

Mokou smiled when she saw her friend's expression lighten, and she quickly poured her another cup as she emptied the one she'd been given.

The next day, Mokou woke up with a horrible headache. She and Keine had stayed up drinking most of the night, and now she was seriously regretting it. Keine herself hadn't even seemed to get drunk, but Mokou had polished off nearly an entire bottle on her own, and had gotten six several times in the wee hours of the morning, and that was only the times she could remember.

Once she'd gotten over the initial headache and wave of nausea as she woke up, she rubbed her eyes and looked around the room, searching for any sign of Keine but finding nothing. Somewhat confused, she slowly sat up and noticed that a blanket had been draped across her shoulders. There was a futon laid out on the other side of the room, along with a note on the nearby bedside table. Curious, Mokou pulled herself to her feet and stumbled over, grabbing the piece of paper and reading the message.

It was from Keine, written in her neat and elegant script, perfect for a teacher. The corners of Mokou's lips twitched upwards at the thought of how neat and serious she was when it came to things like that. Always the scholar, that woman. Unfortunately the smile quickly disappeared as she began to read.

Mokou,

I'm sorry that I couldn't be here when you woke up, but I had to leave in order to make some preparations. I laid out the futon for you, but you refused to be moved. If you're feeling sick when you wake up, you're more than welcome to use the house until you feel better. Unfortunately I'll be away for a few days, but I hope that we can eat together again when I get back. There's food on the shelves if you get hungry-

Mokou stopped reading at that, setting the letter back down on the table with a sigh. So Keine still didn't trust her enough to stick around during the full moon, huh? She had kind of expected it, but it didn't stop her from hoping when she'd gotten so drunk last night. A part of her had desperately wished that Keine would stay with her and look after her, even though such selfish thoughts made her angry. She had no right to demand that Keine stay with her. She had to respect her decisions. If she couldn't even do that, she was a terrible friend.

Glancing towards the futon, she let out a sigh and flopped down. There was nothing she needed to do during the day, and she certainly didn't feel like going out now. She might as well sleep until Keine either came back or she felt a little bit better.

When she glanced out the window when she woke up, Mokou sat up with a start. She had been expecting the sun to have set, but what she didn't expect was for it to be twilight. She'd slept far too long for it to just be twilight now, unless she'd stayed in bed for another whole day. She didn't think that she'd been that exhausted, and she quickly began to clean up the house. Keine must not have returned after all, or she'd certainly have woken her up.

Her lips pulled down into a frown as she folded up the futon, putting it away in the closet. Tonight was the full moon. A part of her wondered where Keine was and what she was doing, but at the same time she told herself it wasn't her business. It wasn't, but…

A heavy sigh escaped her as she left the house, closing the door behind her and heading back to the bamboo forest to retire for the night.

And that was when she saw it. A strange flash of green, just at the edge of the human village and leading into the forest. It was odd, something that caught her attention and piqued her curiosity. Could have just been one of the rabbits, she told herself, trying to ignore the urge to follow it and search for it. Could have just been one of the rabbits, but somehow… She doubted it. She had a feeling that it was something far more important, and after a moment's deliberation she finally gave in. She took off through the woods, and every now and then she'd spot the strange thing out of the corner of her eye.

It went on like that for a while, and just as Mokou was getting frustrated and beginning to suspect she was on a wild goose chase, she found what she was looking for.

She stumbled out into a small clearing, skidding to a stop as she finally got a better look at just what it was that she was chasing.

The woman had her back turned to her, so Mokou couldn't see her face, but she immediately knew exactly who it was. She would recognize her anywhere, even with the change of clothes and the addition of those wicked-sharp horns on her head and the tail peeking out from under her skirt. This was the first time she had ever seen Keine's transformed form, the only time she had met up with her on the night of the full moon. She looked so different, so solemn as she stood, still as a statue. Mokou was almost afraid to greet her.

No, that was silly. This was Keine, this was her best friend. It was preposterous to even think of being afraid of her. Kind, sweet Keine, the woman who taught the children in the human village, who used her power to protect that village from harm, would never hurt a fly.

"Keine!" She called out, stepped further into the clearing. "So this is where you were. I was worried about you, when I woke up and you weren't-" She immediately broke off as Keine turned to face her, freezing in place. The look on her face was nothing like the normal Keine. The blood-red eyes that stared back at her were nothing at all like those loving brown ones. These were cold eyes, the eyes of a youkai.

The eyes of a beast.

"Mokou," she said quietly, her voice soft but not the least bit gentle. She almost seemed as though she were chastising a young child. "What are you doing here? I told you that I had things to do."

Mokou was unable to answer immediately, and her face flushed as she looked down at the ground. She felt guilty now, as if she had done something horrible by following her friend here. Keine was looking at her with a cold and calculating gaze, as though she had broken some golden rule.

"I-I'm sorry. I just saw something, and…" She trailed off, unable to come up with a decent explanation. "But more importantly, Keine! I'm worried about you! You always run away from me on the full moon, I wanted to make sure that you were ok! I understand that you might want to be alone, but… Keine, you can trust me! Please, I just want you to be happy. If you don't want to see me, I can understand that, but I'm here for you! If… If you're just going to wander around the forest alone for three days, then at least know that you can talk to me-" She broke off as Keine suddenly turned to face her, an unreadable expression on her face. She looked irritated, somewhat distressed, but mostly… Pained.

"…You're here for me?" She asked quietly, her voice barely above a whisper, and Mokou immediately nodded, a worried smile coming to her face. She would do anything for her best friend, anything to keep Keine from looking like this on these lonely nights. Keine's mouth was pulled into a tight line, and for a moment it looked like she was about to say something, but she remained silent.

An instant later, she had grabbed Mokou by the shoulders, and the phoenix was shocked by her speed and strength. She was not the Keine she knew. This Keine was very much a youkai.

"K-Keine-" Keine silenced her with a rough and aggressive kiss, her hands grabbing at the fabric of Mokou's shirt. The startled girl let out a slight whine as her friend bit down on her lower lip, her tongue forcing its way inside her mouth and exploring the damp cavern. Mokou's hands immediately grabbed at Keine's shoulders, trying to push her away, but the youkai was having none of it. She overpowered the other woman, knowing that Mokou would never use her full strength in this encounter. A part of her mind, the human part, was already feeling guilty for taking advantage of that, but the carnal need came first.

After a good minute she pulled away, a trail of saliva connecting their mouths as a flustered Mokou looked up at the one woman she truly trusted.

"Keine…" Her eyes widened and she didn't get to finish as the fabric of her shirt was ripped open, buttons flying as Keine looked down at her with those unbelievably cold, hungry red eyes.

"Mokou, I never wanted you to see me like this," she explained as her eyes traveled down the other's figure. "But if you insist… I will accept your offer. You would do anything to help me, right?" She let out a sharp laugh, and Mokou shuddered as she took a step back. "Then you can help me get rid of this pent-up desire. You'll do that, right Mokou? After all, we're friends."

Soooo, there you go. This probably won't be a very long fic, and I don't expect it to get more than four chapters or so. There will be a lemon next chapter, so I suggest to skip that if you're not comfortable with them.