Author's Notes:

I don't own A Certain Scientific Railgun or any of its characters, no copyright is intended.

Italics - Means the person is thinking, just so you know.

This one-shot is a little similar to the previous one, but you will see that they are in-fact very different in many ways :)

Rating for chapter: M (for mature content)

Paring: Mikoto x Kuroko

Warning: This contains yuri (girl x girl) parings. Don't like, don't read simple, otherwise enjoy :D

WARNING: This contains lemon ;P

...

Kuroko's P.O.V:

Today started out as any other normal one, I awoke early in the morning and woke Sissy up, and as normal she groaned a bit before rolling over and siting up in her bed.

"Come on Sissy, we're going to be late,"

"You know you really are like a human alarm clock," Sissy isn't much of a morning person.

"We'll I wouldn't have to be one, if you actually got up early," I normally always had to wake her wake, she has been awake before me once or twice, but that hardly ever happens.

"Fine, I'm up," she yawned as she slowly got out of her bed and sighed, while I looked to that perfect body of her's.

Her short light-brown hair was all tangled up and out of place, she still looked awfully tired, and those green 'Gekota' pyjamas of her's needed fixing up. The top three buttons were un-done and her right shoulder was showing, as she ran a hand through her short hair, and I noticed that she was looked back at me questionably.

"Kuroko, stop staring at me like that, it's creepy," her voice took a firm tone to it as she looked to me uncomfortably.

"Sorry Sissy, I just can't help it sometimes, you are so perfect, it's just impossible to not stare in awe of your beauty," I said it to her a lot, but that was only because it was all true, there was no denying it, she is perfect in every way.

"Yeah….whatever," she replied half-heartily, as she walked away from me, while I sat down on my bed and smiled to her.

I watched those delicate fingers of her's unbutton the rest of her nightshirt, as she slowly slid it off her shoulders and took the piece of clothing off completely, leaving her topless as she held the nightshirt up covering her small (but still perfect) exposed breasts.

'Yep she's beautiful,' I sighed happily as she combed her fingers through her short hair, and glanced to me again, noticing that I was still watching her and hadn't yet started getting changed myself.

"Quit staring already!" she shocked me.

….

Routine slipped back into the morning as we both got changed into our school uniform (I normally do have a shower but I got up a little late today and didn't have the time to), we went down and had breakfast together like we always do, and said our 'Goodbyes' when it was time for our lessons to start.

Sissy is a year older than me so I never really see much of her during school time, plus she normally is with a few of her classmates whenever I do see her in the hallways or sitting in the dining hall, she's hardly ever seen on her own, but it's not like anyone would expect anything less from 'The great Ace of Tokiwadai middle school', however I knew she didn't really like all that attention, in fact there were times when she says she could really do without it.

I wasn't the only one that would stand and admire Sissy from a-far, many of the other girls from the younger year (and even some of the middle and older year) would hang around to get a glimpse of the famous 'Railgun' that went to our school.

There was one other level 5 at our school, she was known as 'The Queen of the school', but she was very different from my Sissy, she abused her ability and used it to manipulate others, plus she thrived on all the attention she would get. Also that level 5 was a year older than Sissy, which meant Sissy went by the title of the youngest esper to ever to make it to level 5, not only that but she was the third ranked level 5, that other girl was only the fifth ranked, she couldn't even match up to my Sissy.

'She's not only beautiful, but she's also unstoppable,'

I didn't always think of her this way, back when I first came to this school, I thought she was just some show-off who liked to use her power to impress others, however when I met her I realized how wrong I was, and all my thoughts of her changed. I couldn't get her out of my mind, she had stolen my heart and I wanted to get to know her better.

So I snuck into her room, and got caught and scolded at, but after the Head-resident punished us both by making us clean the whole dining hall together, from there we ended up bonding and became roommates, and also became close friends. However I also happen to know a little secret about my dear Sissy that no one else knows.

It's not about her love for childish and cute things, quite a few people knew about that (two of them being our other two friends Uiharu and Saten), but there was a secret that Sissy trusted only me with, a secret that is kept under lock and key from the rest of the world.

….

The rest of the day passed by slow as always, same boring old long lessons on stuff we already knew all about, lunch spent in the Library studying by myself, and more lessons to end the day, before I met up with my Sissy and we went to go and hang out with Uiharu and Saten for the rest of the afternoon.

We were sitting outside on the park branches, all having a cool drink together on this partially hot day. Shaved ice drinks were perfect for a hot day like this. Saten got lemon, Uiharu got blueberry, and I got Strawberry, same as Sissy as always.

Uiharu and Saten were talking about some famous singer of some sort, Sissy was daydreaming while looking up at the sky, and I was clinging to her arm, counting myself lucky that she hadn't yet shocked me because I was being clingy, everything was as normal as always.

However it didn't take long for everything to change as I rested my head on her shoulder and she instantly tensed up and looked to me. I smiled back to her with a sigh, expecting her to just either brush me off or shock me, but instead she glared to me and stood up for some reason.

Then I saw that look in her brown eyes that I knew all too well, I was going to get shocked.

I smiled nervously, expecting her to shock me and glare to me, but instead she caught me off guard and did something that took me completely by surprise…she slapped me, hard.

It wasn't just a simple tap, it hurt and made my cheek sore, Sissy had slapped me, causing me to immediately leave her alone and rub my wounded cheek. I was surprised, as was Uiharu and Saten, she had never hit me like that while we were in public like this.

She had done it once or twice back at the dorms, but it was never normally that hard, it never normally hurt, and was only ever used to warn me that she wasn't in the mood for any of my antics, but this slap hurt a lot and made my eyes well up with tears.

"S-Sissy?" I questioned, while I looked to her, she was turned away from me and looked upset.

"Misaka…." Saten and Uiharu looked to her as well as they had stopped their conversation and had both gone a bit speechless from seeing Sissy slap me out of nowhere.

"I'm going back to the dorm," Sissy stated as we all watched her turn and start to walk away from the benches.

Something was wrong, and I wanted to find out what, it wasn't normal for Sissy's mood to change so suddenly and for her to hit me like that.

"Wait Sissy!" I stood up and was going to follow her, when her frim voice stopped me.

"Don't follow me," she wasn't looking to me, but I could tell she was glaring at me, I had made her really mad just now.

"Okay," I replied with a nod as I sat back down on the bench, and we all watched as she ran off to go back to our dorm.

"Are you alright Shirai-san?" Uiharu asked me as her and Saten looked to me with worried expressions.

"I've never seen Misaka hit you like that," Saten added.

"It's okay, I'm fine, I think I just made her mad, she'll calm down if we leave her alone for a bit," I explained with a smile as I nursed my sore cheek and wiped my eyes, so that the two didn't see the tears I was holding back right now.

"Are you sure?" Uiharu asked looking awfully concerned for me right now.

I just nodded to her and sighed slightly, 'Where did that come from?' I wondered as looked back to the direction that Sissy had ran off in, before I changed the topic from what had just happened and us three settled into a much cheerier atmosphere.

….

Kuroko's P.O.V:

I now stood outside the dorm that I shared with Sissy as it was now late in the evening and Uiharu and Saten had gone back to their rooms for the night, while I was hoping that Sissy was in a better mood and had calmed down now.

I took a deep breath and opened the door slowly, sighing slightly when I saw Sissy sitting on her bed with her knees hugged upto her chest, and her head hanging low.

"Hey Sissy, I'm back," I smiled as I closed the door behind me and walked over to Sissy.

"Have you calmed down now?" I asked as I rested a hand on her shoulder and wondered if she would answer me or not.

Luckily she slowly lifted her head and looked upto me, she nodded and wiped her eyes with her arm, she had been crying.

"Sorry I hit you, Kuroko," she apologized in a whispered tone and now straightened out her legs, sitting back on her bed and sighing deeply.

"It's alright, it hurt, but I don't think it'll leave a mark," I stated as I sat down beside her on her bed and stroked her short hair softly. She was back to her regular self now, and I could tell she was more than sorry for slapping me.

"Hey, if you don't mind me asking, why did you do that? You've never slapped me that hard before," I asked, not sure if she would actually answer me or not.

"You were being clingy and annoying, and I was getting bored of shocking you all the time," that was a lie, but I didn't push for anything more, that could very well just cause her to get mad at me again.

"Okay, I'll forgive you, if you kiss it better for me," I smiled hoping to cheer her up a bit, and get her smiling again.

I was joking, but right now Sissy wasn't herself, and so it came to no surprise to me that she actually leaned forward and lightly brushed her lips against my cheek (which was still a little sore, but it didn't hurt anymore), kissing it lightly, before she moved away from me and sighed.

"Thank you," I smiled to her as she nodded while looking away from me, and I stood up, ready to go and take a shower and get ready for bed.

But I was stopped by her voice, "Kuroko,"

"Hmm?" I looked back to her as she was now sitting on the edge of her bed with her legs dangling over the side of it.

"Come and sit down with me again," she patted her bedsheets beside her.

I simply did as I was told without any objection as I turned and sat down beside her again, while she looked to me nervously, she stayed silent for a while, which made me wonder if she was actually going to do anything or not, but I should know the drill by now, after all we've been through this enough times.

"What is it Sis-

I didn't even get a chance to react as she cupped my cheek and pressed her lips to mine, pushing her tongue in instantly and causing me to melt into the sudden deep kiss. She bit my bottom lip and sucked on my tongue, causing me to moan and tremble slightly, I felt her pin me down onto her bed harshly as she now held both of my wrists above my head and kept a tight hold on them.

My heart was pounding, my head was spinning and my body was trembling all over, we had done this enough times now for me to easily guess where it was going. Our kiss broke as I panted heavily, and looked up to her, while she looked back down to me with those dominating eyes that no one else ever saw.

"You really didn't need to hit me, you could have just told me what you wanted…..Mikoto," I stated as I now smiled upto Mikoto and didn't fight her at all, I didn't want to.

"You know full well, that I could never say those things while Saten and Uiharu were with us," she tightened her grip on my wrists and glared to me.

"You could've whispered it into my ear," I wiggled out of her tight grasp and propped myself up on my elbows, kissing her neck lightly. She shivered against me as I bit down on her skin.

"Kuroko, don't leave marks, we can't let anyone know about this," she reminded me as I licked where I had bit down on her skin and sucked on it a little.

"Then stop, I've told you before we can't do this on a school night," I stated as I now sat back and firmly stared to Mikoto.

She raised an eyebrow to me slightly, I don't normally refuse her like this, so of course she wanted to show me who was in charge here.

She leaned down and kissed my neck, "But I want to kiss you, and touch you, besides…." She paused as she looked to me with a smirk and kissed my neck again, "You want to do the same to me right?"

She was completely right, she always was, this was the secret that only I knew about, this was what Mikoto was like when we were alone, and right now she wanted me.

"Fine, but just this once alright," I gave in with a sigh.

"That's my good girl," she whispered to me as I just smiled and rolled my eyes to her.

"You're so spoilt Mikoto," I replied, before she started kissing me again and soon started to remove all of my clothing. Taking off my top and undershirt, throwing them to the floor, before un-clipping my bra and removing it along with my shoes, socks and skirt, leaving me in nothing but my underwear which was already soaked with excitement.

I learnt about this side to my dear Sissy about a month ago, she got mad at me one night for stealing a pair of her childless panties and when I thought she was going to just shock me and snatch them from me like normal, she instead surprised me with a kiss, and from there we ended up having sex for the first time.

I bet no one would ever believe it but Mikoto has a secret side to her, a side that is possessive, aggressive, and above all else terrifying. This was the side to her that only I knew about, she would direct her anger towards me, and I would happily just allow her to. After all how could I possibly resist her when she let me have my way with her body as well?

It may have come to me as a surprise at first, but we had done it so many times now that I could easily tell when she wanted me. But today had been different, normally when she wants to do this kind of thing with me, she just kisses me, or tells me, however this time she hit me, hard. Mind you I guess it's true that we hadn't done it in a while, perhaps I pushed her a little too far with being so clingy with her this time.

Mikoto allowed me to take off her top and undershirt, moaning and panting heavily when I took off her bra and sucked on those beautiful small breasts of her's. Every part of her was beautiful and perfect, which made me feel so lucky that she only ever let me do these things to her, I was the only one she trusted with this secret, she doesn't let anyone else see this side to her.

"Ahhh…..Kuroko…." She moaned as I sucked on her right hardened nub and bit down on it lightly, careful not to leave a single mark on her perfect skin. Her breasts were small and very sensitive, which is why I gave them the most attention whenever we did this.

"Kuro-

Heh, she noticed.

"AHHH! Ah….Mmmm…..you're going that far already?" she asked as she had now noticed just where my knee was.

"You've been turned on since this afternoon right? Don't you want a fast release?" I smiled as I rubbed my knee against her already drenched panties.

"You're not wearing those shorts toady, why?" I asked, making my movements more frim and causing her to bit her lip so she wouldn't cry out loudly and alert the girls next-door.

"I-I forgot to put them on this morning…..I didn't sleep all that well last night and woke up tired...AHH!" I was going awfully slow, but I knew that I was turning her on even more by doing so.

"Take your skirt off,"

She nodded and quickly did as she was told while I increased my movements as a reward. But once she started to roll her hips into my touch, asking for more, I stopped and slowed down, causing her to groan out of annoyance.

"You're such a tease Kuroko," she glared to me and panted slightly.

"Come here and lean over my shoulder," I said with a smile and sat up. She slowly came and did as she was told as she rested her chin on my shoulder and wrapped her arms around my neck, nuzzling into me slightly.

"Don't be too loud okay?" I whispered to her as I wrapped an arm around her and rested my hand on the back of her head, stroking her hair and taking out the clip that kept her long fringe out of her eyes.

I felt her nod as she breathed heavily and I could feel just how hot and bothered she really was. This is what I loved to see the most, her perfect body drenched in sweat, while she would pant heavily and moan out my name over and over again in a lewd and sexy voice that no one else ever heard.

"My Mikoto," I whispered into her ear, as I caressed her covered slit with two fingers, tracing the outline of each and every fold I could feel through her soaked panties, while she trembled and struggled to keep her voice quiet.

I decided I had kept her waiting long enough as I slipped off her panties and started to stroke her now exposed sex, starting off slowly, before increasing my pace, as her gasps and moans of pleasure grew more frequent and were slowly becoming louder.

"Mmmm….Kuroko,"

I kissed her cheek lightly and felt her flinch slightly as I inserted my index finger, thrusting it in and out of her slowly. Soon adding in another finger when her hips started to roll into my touch, begging me for me.

"Ahh…..AH! Kuroko…." She sounded like she was getting close now as I could feel her hot breath on my skin, and her moans were dangerously starting to turn into screams.

"AHHHH! Kuroko….YAAAHHH!"

"Shh…..someone will hear," I whispered to her as she nodded and covered her lips with her hand, muffling every loud moan and scream she let escape her mouth. Her voice was something that would keep me awake at night, hearing it again like this felt like a dream, I didn't realised just how much I missed doing these things with her.

Finally as I thrusted my two fingers deep inside of her, she arched her back and thrusted hard into my touch and reached her climax, while I made her ride out her orgasm and could hear her loud screams of sheer pleasure all being muffled out into small whimpers and gasps by her hand that was pressed against her lips, silencing her voice so that only her and I could hear it. I let her catch her breath as I removed my fingers from inside of her, and kissed her cheek while she slowly calmed down and recovered, panting heavily and moving to let her head rest against my chest.

"Did that satisfy you?" I asked as I showered her neck in light kisses and held her close to me.

"…..Yeah…." She whispered out still panting heavily as she relaxed in my embrace and sighed deeply when she was finally able to get her breath back.

"Kuroko"

"Yeah?"

"Lie down,"

I smiled and let her go as I lay down and let her kiss me deeply, I had had my fun, now it was her turn. She slowly left a trail of light kisses leading from my lips and down to my breasts. I was pretty much as flat as a board and I didn't really get a lot of stimulation from my chest, but it did turn me on an awful lot when Mikoto would slowly run her hot tongue over my breast and flick my perky nubs causing them to become frim and hard.

She always did this since she knew it got me in the mood, and there was no different story this time, but she did it at a much quicker pace as it was obvious where she really wanted to direct all of her attention towards. She came to my panties and slowly took them off, leaving me now laying completely naked on her bed.

It seemed like she wanted to get me off quickly as she wasted no time in causing me to clench hold of the bedsheets in my fists tightly, and moan out her name, while her hot tongue pleasured my slit, and would poke at my clit every few moments, encouraging it to show itself. And sure enough it soon did.

"Ahh….Mikoto….AH!" I felt her sucking on my clit lightly, as she looked to me and smiled at the way I panted and moaned out her name, I could hold back my voice much better than she could, but that doesn't mean it wasn't a struggle for me to do so.

I was constantly biting my bottom lip to keep myself quiet, while Mikoto now started to thrust her tongue inside of me already causing my climax to build up in my lower abdomen. I rested a hand on her head and tugged at her short hair as she quickened her pace and caused me to roll my hips into her hard and fast thrusts.

'Damn this feels amazing,' I thought as I could soon feel my climax approaching and knew that Mikoto could tell that I was close, since she not only doubled her efforts but now she was also sending powerful shocks through my swollen clit as her hand rested over it.

"Ah….Ah…..M-Mikoto!" I moaned out louder as my back arched and my waist raised up off the bed slightly. My teeth clenched together and my toes curled while I reached my limit and I thrusted my hips into Mikoto's advances.

My whole body spasmed violently while I shut my eyes tight and rode out my intense orgasm, Mikoto not letting up for a single second as I could feel her tongue happily lapping up all my juices and licking me clean. I panted heavily, desperately trying to get oxygen into my lungs, while I opened my eyes and felt slight tears of pure bliss stream down my cheeks, squirming slightly as I came down from my high and looked to Mikoto.

She sat up straight on the bed and smiled as I watched her swallow slowly, before she looked back to me and licked her lips clean of my juices and leaned over me, pressing her lips to mine and kissing me deeply.

No one would ever believe that she would have this kind of side to her, it was impossible to think about really, one minute she could be her regular kind and helpful self, obsessing over cute things and being as stubborn as ever. And the next she could turn on me and push me down harshly, kissing me deeply and causing me to moan into her mouth.

I loved her, I loved her with all my heart, but she didn't feel the same, she just directed her anger and desire towards me, I was merely her close friend and roommate that she lusted after. She was truly someone to be scared of, but I could never stop loving her, and I never wanted her to change, whether she was my dear Sissy or my dominant Mikoto she was still mine, while I was her good, submissive girl who never refused her. We belonged to each other.

….

"Kuroko?"

I heard Mikoto call to me as I was now still laying on her bed, but was facing away from her, while she was sitting up on her knees beside me and looking to me.

"What is it?" I asked, not looking to her as I was just about ready to fall asleep, doing these things with Mikoto always makes me exhausted, and so I was now laying relaxed, still completely naked and drenched in my own sweat, as I looked over to my bed, and could feel my eyelids growing heavy.

My attention was brought back to Mikoto as she leaned down to me and stroked my cheek lightly (the cheek she had slapped earlier), while she kissed me and sighed a little.

"I really am sorry for suddenly slapping you like that," she kissed my lips lightly and I could see the genuine look of worry and concern in her brown eyes.

"It's fine, it doesn't even hurt anymore," I smiled as I cupped her cheeks and kissed her back lightly.

She rested her head on my chest and nuzzled into my neck slightly, cuddling up close to me, "You'll stay with me tonight, right?" she asked.

"Of course, Mikoto," I replied as I happily wrapped my arms around her and held her in a loving embrace, while she pulled her covers over us both and settled against me.

I reached my hand up and stroked her short hair, watching her slowly drifting off to sleep in my embrace and just thinking of how lucky I was to get to hold her like this, she was so beautiful in so many ways, I didn't believe I deserved her, but as I lay there in her bed holding her close to me while she fell asleep in my arms, I knew I never wanted to let her go, as I treasured this wondrous moment and was soon joining my dear love in a peaceful sleep.