Disclaimer: Mikasa Ackerman and Eren Jager (and the others) are all property of Isayama Hajime, I do not own them, I'm just using them for this little story.

I got bored and thought this'd be an interesting (probably already thought of) idea and I rolled with it. Anyway, yeah don't forget these two aren't related in any way so don't go messaging me crying INCESSSST because if you watched/read the damn anime/manga you'd know she was fostered by the Jagers so THERE IS NO BLOOD RELATION THEREFORE NO INCEST. Also ugh, hate that stuff.

Anyway, enjoy, please note that sleep deprivation is what got this written so yeah

Mikasa had frequent night-terrors, and because of this she was given her own room in the HQ. In the shared dorm she often woke the other female Scouts with her shouting or sudden movements, she had almost assaulted one of them by accident one night when they had attempted to get her sleep-fleeing-self back into bed. So, after consideration and many complaints, she was put in her own little room far away from others. Eren hadn't been informed of this, and he didn't find out for weeks after. He had thought her night-terrors had gone away, as she had gotten them as a child in his home too. They were a result of her PTSD, naturally, as she had witnessed the brutal murder of her parents, and of course the brutal murder of those who had killed them.

When Mikasa had first been brought to Eren's home, there was no spare bed, and as they were young children, Grisha and Carla had allowed the two little ones to share. Eren was fiercely protective of her at the start, he had saved her after all, and he wanted to keep her feeling safe. At night the two of them would hide beneath the covers, and he would hold her hand in both of his as he waited for her to sleep. A few weeks after this arrangement, she had begun to have night-terrors. The first night was a horrible shock for the 9 year old boy, as he had never experienced such a thing in his life. She was up, out of bed, crying hysterically and shrieking into her hands. He had tried to calm her down but she had just fought off his attempts and hid herself in the corner. Grisha soon appeared, with Carla, who sat with the frightened girl until it passed and she was calmly asleep again. Eren's father explained to him what had happened, and assured the boy they would pass with time. Eren grew used to these interruptions to his sleep, and it became the norm for him to be the only one in the room with Mikasa when it happened. Just before the loss of the outer wall, Mikasa's night-terrors had faded. They also no longer shared a bed, which he found a little sad because he had grown used to cuddling the girl after her calming. Now, 6 years later, he found out that once again she was being tormented at night. He had overheard Connie and Jean talking, as the latter had once again brought Mikasa up in conversation. "Sasha says her new room is really cold, there's no fireplace in it," the bald Scout said as he carried his boxes. "Is she really that bad to need her own room?" Jean had asked curiously. Eren frowned at this, looking to the pair. He had tried to focus on his current task, which was feeding the horses, but he was concerned now, "guys, what's up with Mikasa?"

"Oh you didn't know?" Jean could barely contain a haughty smirk. He put down his boxes, "your sister has really bad fits at night, according to the girls. She had to be put in her own room because she was disturbing everyone else."

Eren's frown deepened, and he dropped the hay he had been feeding the horse, "take over, Jean-Bo."

He ran past the angry male, he had to go check on Mikasa, she never mentioned this to him, why had she not mentioned this?

"I didn't think it mattered," Mikasa replied with a blank face. She was cutting up vegetables for a stew in the kitchen. Eren sighed in annoyance, "of course it matters! It means you're not ok up there!"

He had poked her forehead as he said that, causing her to jump slightly and look at him with a little frown of her own, "Eren, don't do that."

"I just want to make sure you're ok," he replied, trying to mask his worried expression, "you're my Mikasa, I have to make sure nothing's wrong with you."

The girl gave a shy smile at that, her eyes on the carrot she was chopping up, "you have chores to do, Eren, go do them before that midget bastard uses it as an excuse to kick you."

Eren watched her for a moment before nodding, walking away then. He turned on his heel before he reached the door, marching back to give her a quick little hug from behind before leaving the room. Mikasa was still smiling.

Later on, after bedtime, Mikasa was in her room preparing to go to sleep. She pulled her nightdress on, brushed her hair, and washed her face with the cloth and bowl of water she kept on her desk. It was chilly in there, she could see her breath. She wasn't very happy having been moved, but she knew it was better for everyone that she be in there alone. She missed listening to the whispers and hushed giggles of the girls around her though. She frowned when she heard a knock on the door, no one was meant to be out after bedtime. She cautiously approached the door, opening it a crack to peep out. "Hey, let me in," Eren smiled, standing barefoot outside her door in his raggedy pyjamas. She opened the door fully as she looked at him in surprise, "Eren, you should be asleep!"

"I plan on sleeping soon, if you'll allow me to come in," he said with a soft laugh. He walked in anyway, looking around her little room curiously, "it's cold in here, Mikasa, I wish you could've been given a nicer room."

"Well I didn't exactly have a choice," she said as she closed the door, still confused by his presence, "what are you doing here?"

The male smiled and went to pull her close for a warm hug. After all those years, he had finally grown taller than her, and broader. Mikasa couldn't help but smile at his warmth, her arms wrapping around his waist as she nuzzled his shoulder. "I'm staying with you tonight, to help with those nasty night-scares," he said as he rubbed her back, still not releasing her. "If you get caught, Levi will kick the crap out of you, he seems…strange about you," she said as she looked at him. The brunette released her with an amused grin, "I don't mind, as long as I can make you feel safe and ok, got it?"

Mikasa rubbed the back of her head shyly as she watched her closest friend get into her little bed. They hadn't shared since they were children, they were grown now, their bodies and thoughts and minds had changed. "Not want to cuddle me?" Eren asked with a smile, he was lying on his side to make room for her, "y'know, I've missed it. I liked having you close to me."

Mikasa felt her cheeks flush as he said that. By reflex she reached to pull her scarf over her nose, but as she had been preparing for bed she wasn't wearing it, it was resting on the back of her chair. Eren grinned as he watched her, "come on, it's cold, I can see you shivering."

She nodded slightly, and went to blow out the candle by her bedside before carefully slipping in beside him. She smiled, Eren had immediately put his arm around her to hold her close, giving a relaxed sigh as he rested his head by hers. "This is nice.." he whispered, gently rubbing her side, "things are always so crazy, or people are causing trouble, I think I needed some time like this.."

"I haven't heard you talk like that before.." she replied softly, his breath on her neck was making her skin flush again. "I get so wound up, I can be a real jerk," he mumbled, frowning as he nuzzled her slightly, "I try to relax, it's just hard, and I feel bad for snapping. Especially at you."

She smiled at that, turning her head to try and see him in the gloom, "considering what we do, it would be strange if you could be calm and relaxed most of the time. I know you don't mean to be harsh."

"Doesn't excuse it though, I'm sorry," he whispered, a sad note clear in his tone. Mikasa snuggled closer to the boy, rubbing his arm, "if I had to do what you do, I would be just the same."

"You're really warm now," Eren said, still rubbing her side, "are you feeling ok?"

She nodded with a little "mhm", but really she was just finding his close proximity and his touch was having a weird effect on her. She found herself practically steaming then when Eren nuzzled her cheek and kissed it lightly, "sure you're not sick?"

"I'm fine, Eren, don't worry," she replied back, fast and quiet. Though she couldn't see, Eren raised an eyebrow, an amused smile on his face. "You seem a little flustered, was it this?" he kissed her cheek again, just to see her reaction. Mikasa nibbled her lip and turned on her side, her back to him now, "goodnight, Eren."

"Hold on a second.." the male pulled her onto her back again. He carefully climbed on top of her, knees either side of her thighs as he leaned in close to get a better look at her face through the gloomy dark. His hands rested either side of her head, as she watched his shining eyes piercing hers. "What are you doing…?" she whispered, she could feel his breath on her lips now. "I really want to kiss you," he whispered in reply, the words turning her scarlet, "can I, Mikasa? Just one?"

"Well…yeah, but why?" the question never received a reply, as soon as the words were out of her mouth, he kissed her firmly, one hand moving to cup her cheek, his thumb tracing along her scar. Mikasa's heart raced as he continued to kiss her, only stopping momentarily to breath and get a grip on the situation. Once that grip had been got he immediately kissed her again, both hands on her cheeks now as he did so. For someone who had no experience, he was a passionate and loving kisser, he sent tingles down her spine, he made her body react in such alien ways. She found herself gripping his threadbare shirt as she kissed him back, moaning softly as he slipping his tongue into her mouth to rub and tease her own. Eren shivered when he heard that little sound, one hand moving down to lightly cup her breast through her nightdress. He was so curious about her now; he wanted to know how she had changed. He wanted more of her kisses, and more of her in general, in ways he really didn't understand but his body just made him feel were right. "E-Eren.." she whispered as he moved his kisses to her neck, her body tensing at his little nibbles and the feeling of his hand groping her. "I-Is it too much..?" he whispered back, snapping out of his little daze for a moment, "I'm sorry, I only wanted a kiss…"

She hushed him with a little loving kiss of her own, "just…slow down…"