Author's Notes:

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

Italics - Means the person is thinking just so you know

This fanfic is a yuri (girl x girl) don't like? Don't read simple, otherwise enjoy.

...

Mikoto's P.O.V:

Kuroko and I have only been roommates for a couple of weeks now and I'm really starting to see…certain changes in her. She's not that shy girl that would blush, and/or act nervous when she was around me anymore, instead she now happily hangs off of me, and clings close to me all the time.

Her attitude to me being the 'Railgun of Tokiwadai', and the fact that I may use my ability at unnecessary times has become awfully annoying. She's bossy and very stubborn, she's always scolding me for getting into fights, or for when I stay out late past curfew. No matter what she'll always be awake and waiting when I get back, ready to give me a good telling off.

'Misaka-san, how many times do I have to tell you? You can't keep staying out past curfew like this, honestly do you know how many times I've had to cover for you?' she would just go on and on at me like I was some kid that couldn't take care of myself, and she's meant to be an underclassmen of mine.

'I really don't know how your old roommate handled this,' she would say with a sigh, while I just stared blankly at her, 'Hey are you even listening to me?' half of the time I wasn't.

Truth to be told my old roommate and I were never all that close, and she hardly spent any time in our dorm, I was actually the one covering for her most nights. And to be honest, to me it seemed like she was more than happy, when I talked to her about Kuroko being my roommate instead of her, I guess she didn't like me all that much.

So Kuroko's demanding side is annoying from time to time, but at least I can just block her endless lecturing out, her other tendencies are a different story, and it's not as easy to just ignore them.

She doesn't like me leaving our dorm room alone (especially in the evening), she won't let me near any guys for some reason, I've often caught her going through my stuff (partially my underwear and other clothing), she sometimes seeks into my bed at night, or comes into my shower and clings to me tightly, she has tried to kiss me and grope me quite a few times, and she just won't seem to leave me alone, and when I try to get away from her, she just teleporters to wherever I am, no matter where I go, she always finds me somehow (that power of her's can be a real pain sometimes).

I found out that she's in Judgement about a day after we became roommates, and when she is busy with them, is the only time I get some peace, and can actually have some time to myself.

I often find myself having to shock her about a hundred times throughout the day, and half the time she seems to actually enjoy me frying her to a crisp. I've realized now that she's a lot more perverted than she used to be, especially towards me (but to be honest, that's probably my fault, I no doubt brought out this side to her, when I did all of those thing to her at that party).

Meanwhile my strange desire and crazy attraction towards her have now gone completely. I don't feel the urge to kiss and touch her anymore, I don't grave her taste anymore, she's not on my mind all that much now, I don't lust after her or her body anymore, and it seems like my mind and body are satisfied now.

And although putting up with Kuroko's strange and annoying ways can be such a nuisance sometimes, it's not like I can blame her, after all I'm the one that did way worse things to her not too long ago. So now I guess I kinda see it all as an ironic sort of punishment for all those things I did to her on that night. Besides she can be a good friend a lot of the time, so being her roommate is actually something I enjoy…most of the time.

But while all that has changed and I'm getting used to living with it all, what really surprised me was the day that she decided to stop calling me by my name, and started to call me something else…

….

Writer's P.O.V:

"Okay Kuroko the bath's ready for you," Mikoto stated as she walked out of the bathroom, while she was wearing an adorable pair of 'Gekota' pyjamas, along with a white towel hanging loosely around her shoulders, since she had just finished drying her hair.

Kuroko was sitting on her bed facing away from the older girl as she blushed slightly. Mikoto noticed how unusually silent the younger girl was being, and looked to her with a concerned look in her eyes, before she walked up to Kuroko's bed and sat down on the edge of it.

"What's up, you seem a little down?" Mikoto asked as she rested a hand on the Teleporter's shoulder, and smiled to her slightly. "Kuroko?" she called to the younger girl again, after not getting any response from her.

"Why do you call me that?" Kuroko finally replied to the older girl in quite a low tone.

"You mean, 'Why do I call you by your first name' right?" Mikoto asked seeming a little unsure.

Kuroko just nodded in reply, while still not even looking to the older girl.

"Well we've been through so much even though we haven't know each other for very long, besides I thought it would suit better to call you by your first name, since you're more than just another underclassmen to me. You didn't seem to mind me calling you by your first name before, what's different now?" Mikoto asked.

"Nothing, it's just…well pretty much everyone calls you by your last name, so would it be alright if I called you by something else?" Kuroko asked nervously.

"Sure, I guess," Mikoto nodded slightly.

"Okay, well I can't call you by your first name, because I'm an underclassmen, which would be very disrespectful," Kuroko stated as she thought for a minute. Mikoto just looked to Kuroko as the younger girl sat there thinking.

"Hmm, how about 'Senpai'?" Kuroko asked.

"That sounds kinda creepy," Mikoto thought out loud.

"Misaka-sama?"

"Isn't that still calling me by my last name?"

"Misa-chan?"

"That makes me sound like a child,"

"Railgun-san,"

"Now that just sounds weird,"

"How about, 'Sissy'?" Kuroko asked, as she was slowly running out of ideas for names now.

Mikoto paused for a moment as she thought over the last name that Kuroko had suggested to her, "Well, I guess it would be alright for you to call me that," she stated nervously as she looked away from the younger girl now.

"Can I call you 'Sissy'?" Kuroko asked as she now turned round to face Mikoto, and reached a hand up to the older girl's cheek, "Would that be okay?" she asked as she stroked the Railgun's cheek lightly.

"Umm…sure," Mikoto replied as she blushed slightly, while she looked back to Kuroko.

"YAY! I'm so happy Sissy!" Kuroko cheered happily as her face lit up with delight, before she wrapped her arms around the older girl's waist, and hugged her tightly.

"Hey Kuroko, what are you…w-where are you moving your hands to?" Mikoto asked as her eyes widened at the sudden hug, and she gasped slightly, as she could feel the younger girl's hands moving down her back, and towards the hem of her pyjama pants, while her blush deepened slightly.

"What do you mean Sissy? I'm not moving my hands at all," Kuroko stated innocently as she slightly smiled to the older girl.

"Kuroko, stop it," Mikoto warned as she could feel one of Kuroko's hands slip down into her pyjama pants, and gently started to massage her rear.

"Stop what Sissy? I'm not doing anything besides hugging you," Kuroko stated as she continued to play innocent.

Mikoto sighed slightly, before she glared to the younger girl, and gave her a good shocking, to the point where the Teleporter's body had actually turned from her normal light pink colour, to a darkly tanned colour.

Kuroko immediately let go of the older girl, as she sat on the bed shaking uncomfortably, while she tried to recover from all the powerful shocks, which were still coursing through her body slightly.

"Just go for your bath already, will you?" Mikoto instructed as she folded her arms and got off of Kuroko's bed, while she was still blushing slightly, but now was turned away from the younger girl.

"Right, sorry Sissy," Kuroko apologized sheepishly as she smiled nervously to the older girl.

Kuroko quickly went into the bathroom as she didn't want to anger her 'Sissy' any more than she already had.

….

Writer's P.O.V:

Mikoto was now sitting on her own bed as she sighed slightly with a smile on her lips, while she waited for her roommate to finish in the bathroom and get back into her own bed.