AN: Since the smileys weren't exactly popular, I'll leave them out. They were more limited than I would've liked, anyways.

-FrodoFighter: Before your critiques, I'll come out and say that she was thinking of Goku. Yes Goku. You know, 'a certain super-human shounen manga hero'. Also, I didn't know this for a long time myself, but Touma's hair is not naturally spiked. No, seriously, look it up.

1. Others have also complained about this, so as stated, I'll just leave them out. Just thought it'd be a nice quirk for the MCs.

2. You really think Mikoto actually takes 'no' for an answer when it comes to his welfare?

3. Thanks, gets me every time.

4. I actually agree with you there, but we seem to be somewhat alone judging from some of the anime out there. At least I'm not royally pushing it with 10-12 year-old girls that have milk spilt on them. (I'm looking at you, Ro-Kyu-Byu!)

I personally suspect that Mikoto is outright genetically susceptible to falling for Touma. I mean, seriously, they're Moms and Dads are quick BFFs, her Mom approves of him, and do I need to mention that all but 2 of her clones are crazy into him?! And the collective will born from that network!

Did someone order a round of fluff? Yessir, it's waiting for you right after this AN. Otherwise, why would I tag this as a Family/Romance fic? Action, Comedy and Supernatural all take a back seat here.

Sisters-Arc will be...next volume(s). No, you read that right, this specific part of the story ends at the Dragon's Breath Feather. I'll tell why then.

I hope the same thing, though from the looks of it, she might not be the only one, I've seen a game-pic of her & Index ready to marry Touma, and you can tell it's Touma from their dissatisfied faces.

-wildarms13: All my ToAru fics will follow the combined timeline of RailDex. Glad you enjoy this!

-UnknownSoul: This fic was inspired by an IchiRuki Bleach fanfic with a similar setting, except completely AU, unlike this, which is mostly cannon.

But of course, just beyond the AN here.

I'm making a short list of the adventures that she won't be involved in due to being an esper. Obviously, these will all be B4 WW3.

-Majin Othinus: Seeing as how it's so integral to the cannon plot, I do not plan on completely removing the Sisters in any of my ToAru fics. Change, yes—remove, no. Though predictably, the changes here will be more than just affecting the outcome – they will affect their relationship.

-ShadowDeath01: Let's just say Mikoto's gonna hafta fight long and hard for Onii-chan.

-Riibas: As you've guessed, making her his step-sister both improved and complicated their relationship. Even more so when, to my knowledge, Japanese will call incest on even two non-blood-related members of the same family getting together, and I don't just mean step-sibs, either. (They don't do that with cousins though... ._.?) If I am mistaken about this, please feel free to correct me, anyone.

CAUTION! Immense Fluff inbound! Subclass: Cotten-Candy with...!

10 year old Misaka – no, Kamijou Mikoto now, was on her way out of school on her first day after fall break. Just last week, her Mama and Touma's Papa had married, and while Touma had taken quickly to her Mama (more like, he went along with her weirdness, as far as the little girl could tell), she had a feeling that it would be a long time before she started to call Touya-san 'Father'.

Certainly not 'Papa', that one was taken.

"Ah, Mikoto-chan!"

For a moment, she thought her Mama had somehow made it into the city just to see her (it wouldn't be the first time), but then she realized that the voice belonged to someone else. When she looked, Mikoto saw a familiar boy waving at her.

"! Onii-chan!"

Kamijou Touma was a little out of breath, having run all the way over from school to pick up his new sister. As scared as he was that his right hand's bad luck would take her away from him at any moment, he was undeniably excited to spend time with her.

"...So how long are you gonna sulk?"

"I'm not sulking."

Having come home after being chased by his (step-)sister, Touma was currently preparing supper for them both. His mind went to the situation next door with a similar setting, except that there, the one cooking was the visiting step-sister.

'Doesn't mean I'm anything like Tsuchimikado,' he thought, 'I just really enjoy spending time with Mikoto, you don't see me singing the praises of Imoutos and Ojou-samas, even though I can't deny Mikoto's cuteness.'

He smirked.

Mikoto, meanwhile, was pretending to watch TV while in the final stages of calming down from her bout of jealousy earlier. Physically, at least.

'Goddamnit, I'm acting all clingy again, aren't I? Aren't I!? Even though I've told myself not to who knows how many times! But I just can't help it! Just the thought of one of those girls taking Touma away from me-! Waitwaitwait, no, stop, bad thoughts! Bad thoughts! Out! Sit! Roll over! Play dead!...What the hell is wrong with me~...?'

"Supper's do– Mikoto, are you okay? Why are you holding your head like that?"

"N-no reason."

He looked at her a moment longer before shrugging and setting down their food, on opposite sides of the table, then turned off the television.

With narrowed eyes, Mikoto asked: "What're you doing?"

"Huh?"

Scooting over, she insistently pointed to her left. "Com'ere."

"...You're not mad anymore?"

With a wry smile, she said: "Nope."

Leering suspiciously for another second before accepting that answer, Touma moved his dishes over next to her.

Sharing a quick smile, they both said: ""Ittadakimasu.""

"Onii-chan, watcha doin'?" asked little Mikoto, watching her new brother busy himself in his kitchen. Turns out their parents, mostly her Mama, had gotten some words in edgewise to the city so she could live in Touma's dorm, who immediately took it upon himself to pick her up every day from elementary school. Most of her belongings were still in her old dorm, but he would help her move them tomorrow.

"I'm making supper," he said, in the same way one would say 'the sky is blue'. As a level 0, he had known that he needed to make use of as many money-saving methods as he could, but after finding a certain joy in hand-cooking his own meals, he forewent instant noodles and the like whenever he could afford it. That was going to be easier, now that Mikoto was pitching in with her level 2 budget.

This dorm was not much different from his future one, there was enough space to accommodate the young girl. She would have to part with some stuff to save room, but she immediately asked for a full shelf for her own use. What for, she wouldn't say just yet.

The little girl widened her eyes. "You can cook?" Looks like her Onii-chan was more amazing than she thought. Even without the hero-spikes in his hair. Hm, maybe she could fix that.

"Ah, I'm not very good at it, but yeah, I can," he answered modestly, though he really didn't have a second opinion on his culinary designs, and the boy realized that his own thoughts were likely biased.

After supper, they both sat on his bed, with her in his lap and their left hands latched together, fingers intertwined.

"Remember the first time you cooked for me?"

"How could I forget, you praised me like I had invented the remedy for world-hunger."

"Well, you are a good cook."

"That doesn't always turn out so well, you know. I've heard of people who couldn't improve because of their faulty sense of taste."

"Well then obviously, Touya-san and Shiina-san made sure you didn't get that."

"Right...hey."

"Hm?"

"Remember the first time you spiked my hair?"

"...(mumble)You don't seriously expect me to forget that, do you?"

Mikoto turned so that she leaned against his chest, nuzzling her face into the crook of his neck, ignoring, for once, her heated face, because of which she couldn't feel Touma's doing the same.

Despite that, he smiled, putting his arm around her in a gently tight hug, his eyes locking onto the bookshelf mostly filled with Gekota merchandise.

"? Mikoto, what is this?" asked Touma at their first family Christmas Party, holding up her present for him. The ones from his parents were as yet unwrapped, since he didn't want to agonize over what she got for him.

"It's hair gel, silly," she replied, setting the collection box from Touya next to the dress from Mama before grabbing Touma's present, which looked like a folded sheet of paper. Always save the best for last, she says.

Frowning in confusion, the boy asked: "For what?"

Setting the still-wrapped present down, she reached for him, getting his left arm when he twisted himself around.

"Come on, I'll help you."

"With wha- hey, don't pull!"

A few minutes later, Mikoto presented Touma's new look to their parents.

"Oh! Nice style, Touma!" Touya was already wearing the scarf Mikoto had bought him and had brought out the camera Misuzu got him, with one of Touma's science-styled stickers on it already.

"Wow, now Touma-kun looks like a hero, ne, Mikoto-chan!" Misuzu on the other hand had set Mikoto's mittens aside for the moment, but had her new necklace (basically a string of bolts and nuts) and the earrings from Touya on.

"M-mama!"

A hero? Now that he thought about it, his newly spiked hair did look a lot like that of those protagonists from Mikoto's shounen mangas. Well, aside from the obviously amateurish look of it.

"...Wait, heroes have to deal with all those problems happening to the world, right?! Is this some sort of foreshadowing that I'm in for a rollercoaster of trouble!? Fukou da!"

"No way, you weird Onii-chan," replied Mikoto as she opened Touma's present for her.

"...Onii-chan?"

"Hn? Yeah?"

"This is...?" She pointed at the hand-drawn Gekota.

"Ahh, Misuzu—Mom said you liked that frog, but since I didn't have the allowance to by any of its stuff, I drew it instead. Is that—"

The boy found himself with a hug-full of happy sister. "I love it, thank you Onii-chan!"

'Holy crap. How long is this good luck streak gonna last?! If I'm not careful, I'll get used to this!'

Nonetheless, he returned her hug as she nuzzled her face into his neck. This drawing was going with the other Gekota merchandise on her shelf in the dorm.

"...Now that I think about it, maybe you were right."

"About what?"

"Me setting you up for all that trouble."

"Wha—nononono, I wasn't accusing you. Besides, you know my luck. That stuff would've happened anyways."

"But sti~ll..."

"Actually, it's the opposite."

"?"

"Every since I met you, my troubles have been more bearable."

She fell silent for a moment, thinking: 'Not last year, they weren't...'

"Mikoto?"

"You're not gonna go sis-con on me, are ya?"

"How can you say that with a straight grin like that?! Don't lump me in with Tsuchimikado!"

"Let's skip your failed Japanese and focus on the fact that you do, actually, agree with him when he says little sisters are the best."

"Err, not quite."

"...Hah?"

"What's with that pissed off voice? I'm just saying that not just any little sister will do—"

"!"

"My little sister is the best!"

"Mmmrgh! I'd shock you if you'd just take your hand off!"

"Look, just 'cause you're embarrassed doesn't mean I have to suffer for it!"

"You do if you're the one causing it!"

"Ow! My ribs! Give, Mikoto, I give! I'm at fault here!"

"There. Good boy," she said, patting his head.

"...I can't tell if I'm your brother or your dog..."

"Isn't it obvious?"

"?"

"You're the best!"

"...Are you avoiding the question?!"

"Shut up and give me a hug."

'I can't tell if she likes hugging, she almost never lets Mom, she basically demands it when we're alone, otherwise it's a no-no, and Pops still hasn't tried yet. Hurry up Pops, I need a clear answer on this!'

Not once did their left hands separate.

"Wait, weren't you just—shutting up now."

"Onii-chan, could you stop apologizing? It's not your fault!"

"No, no, no matter how you look at it, you don't just randomly sprain an ankle in the middle of an empty road. And where did that soda can come from, anyways?"

The two step-siblings were on the side walk on their way home, Mikoto sitting down to Touma's right due to a hurt ankle, Touma crouching down because he inspected it and knew why it happened—she had grabbed his right hand and subsequently tripped on an empty can rolling across their way when he tried to shake her off.

The little girl was failing to convince the boy that he was not to blame, since he would hear none of it. She had seen firsthand how most people reacted to his strange luck, and quite frankly, it pissed her off. Superstitions or no, he clearly wasn't doing it on purpose.

Now, how could she make Touma feel better and satisfy his unnecessary guilt?

"Carry me."

"What?"

"If you say it's your fault, then take responsibility. Carry me!"

"Where?"

"The hospital, of course! And then home, obviously! Or did your head also slip on a can?"

He couldn't help but laugh at that, even as she sparked at him (which he literally waved away).

"Alright, alright. As you wish."

"Need me to carry you?" Touma asked teasingly as he walked her to the Tokiwadai dorm.

Instead of responding, she stuck her tongue out at him with closed eyes as she walked slightly behind to his right.

They came upon the entrance a few minutes before her curfew, something they had practiced with trial and error for almost a year now. And they most certainly remembered the errors.

Turning back to Touma from the entrance, Mikoto raised her left hand, showing off a perfectly circular, white scar centered beneath the gap between her ring and middle fingers.

Touma returned the gesture, revealing an eerily similar scar on his own left hand.

"See you tomorrow."

"See ya."

Breathlessly, 13-year-old Mikoto arrived at the hospital in District 7 where Touma had been admitted at. She dashed to the reception and let them know she was here. She didn't need to ask which room he was in.

"How is he?!" she asked the frog-faced doctor.

"He's fine, just...you should see for yourself first," he suggested.

Immediately, she burst into the room, startling Touma.

"Jeez, Mikoto, don't scare me like that!"

It took her a moment to respond.

"Don't scare you?! I'm the one who got told that you were in the emergency room!"

Though evidently, that was no longer the case, despite the many bandages that she could see.

So why had the doctor used that vague response?

"What the heck were you doing, anyways?!"

"Well, I...huh?" during his response, his frown at her behavior became a look of confusion, "I was, uh, helping...someone, I think. Strange, I can't remember. It's all kinda hazy."

Catching the girl's eye, Heaven Canceller motioned her to come out.

"Just a sec, be right back," she said, earning a nod in return.

"As you can see, physically, he's perfectly fine. He lost a lot of blood, but thanks to his charge, he was kept stable enough for an emergency-transfusion."

"What do you mean, how bad was it?"

"I'll be frank."

The doctor to a deep breath.

"According to the onsite surgeon, he almost didn't make it."

"..."

"In fact, if the girl with him hadn't been a telepath, he wouldn't have. She stabilized the blood pressure in his brain enough for a safe transfer."

"..."

"Unfortunately, this came with a rather sad side-effect."

"...His memory?"

"Not just that one. If the mind is like a computer, and the memory portion like a memory card, then her specific place in it is crippled."

"Wha...how..."

"He will never remember her. Every time they meet will be the first for him, and he will instantly forget her name, face, voice, words, everything. At best, he will get a vague sense of déjà vu."

"..."

Stunned from the large amount of information she received, Mikoto walked back into Touma's room.

He just noted her, opened his mouth, but closed it again.

One does not simply make small talk after three months of receiving the cold shoulder.

With her face in her hand, one question rose to the forefront.

"...Why?"

"Huh?"

"Why didn't you call me, or text me, or..."

"Why should I?"

She looked up in shock, not just because of the words but more so because of the tone he used, which was anything but hostile, as he looked out of his window.

"You made it pretty clear that you didn't want me causing trouble for you anymore."

Instead, he sounded depressed, sad, lonely...

"What kind of brother would I be to not respect your wishes?"

Self-deprecating.

She wanted to slap him, even had her hand up already. She wanted to scold him, tell him how stupid that was.

Then her eyes fell on his right hand.

And it clicked.

He didn't believe it was her fault.

Not this incident, nor even her recent behavior.

He blamed his hand.

His luck.

Himself.

"I...that...no..."

He looked her way again, wondering about her sudden change in tone. It was all the warning he got before she ran up to him and hugged him, tightly.

"Wha—Mikoto!?"

He had thought his luck with her had run its course. So why was she acting like this?

"That's not it!"

Mikoto broke down in tears at the realization of what she'd done.

"I was, I was trying to be dependable, to not be a bother, or a burden! I didn't want to seem like a clingy little sister who'd just be more trouble for you! I didn't, I, *sniff* I didn't mean to, to, p-push you away!"

Touma dumbly held onto the girl as she tearfully apologized.

"I'm sorry! Onii-chan, I'm shorry, I'm sho shorry!"

"You, you don't hate me?"

"NO! No, I don't, I never could! We're family, you idiot!"

The boy himself teared up as the revelation settled in. He held her in a tight, but gentle and heartfelt hug, the same that he would always give her from then on, unfettered by the doubt that had plagued his mind all of these years.

Thereafter, Mikoto had her first face-to-face meeting with Shokuhou Misaki, who declared her (basically eternal) animosity towards Mikoto. (More specifically, she said that she could only forgive her if Mikoto could fix Touma's brain damage, and they both knew she couldn't.)

She also admitted that Touma's convictions were the only reason Mental Out hadn't exacted revenge on the Railgun in lieu of erasing her existence from the memories of everyone important to her, or something along that line (aside from the fact that it wouldn't work on Touma, followed by him suffering for Mikoto's sake, which Misaki didn't want).

This made Mikoto feel even worse, because even without actively doing it, Touma was protecting her.

Even though she didn't deserve it.

Because it was her fault that he almost died.

"Mikoto?"

"Wah!"

A few days later, Mikoto met Touma again at the Seven Mist Mall, having separated from her friend Uiharu Kazari to secretly try out a cute set of p-jays (well, assuming one liked Gekota).

Her step-brother came upon her with a familiar little girl in tow.

"Ah! Tokiwadai Onee-chan, it's you!"*

"Eh? You're...that girl with the bag."

"This girl here got lost. I'm helping her find her mom."

"Helping out another girl? Why am I not surprised?"

"Yeah, yeah, laugh it up. We'll be going, then."

"Wait a moment, I'll come with."

"Nono, even I can do this much by myself."

"Are you kidding? With your luck, you'll get into a misunderstanding with the mother and need saving from her by her kid."

"...Why can't I think of a good retort for that?!"

"Um..."

They both turned to the little girl as she spoke.

"Are Onii-chan and Onee-chan a couple?"

Sputtering red-faced, the two of them were a little quick to deny that.

"Wha—no! No we're not!"

"N-no, no, wha-wh-what gave you that idea?"

"You look like those couples on TV."

"Ah, no, no, you see, Onii-chan here is Onee-chan's Onii-chan."

"Eh? Onee-chan's Onii-chan?"

She looked at their faces.

"You don't look like it."

"A-ah, you see, my Mama and his Papa married each other, so now we're siblings."

"Eh? What about the other Mama and Papa?"

They both fell silent at the innocent question, before Touma replied in a small voice.

"They both went to heaven."

Mikoto nodded, prompting the young child to apologize.

"I'm sorry. Did I make you two sad?"

"It's okay," Touma waved of her concern, "it was long ago."

Looking at his sister, he decided to take the little girl elsewhere.

"Let's go look for your Mommy, 'kay?"

"Okay. Bye, Onee-chan!"

"Y-yeah, bye."

"See ya later, Mikoto."

In late November of the third year since Touya and Mizusu's marriage, their (step)son paid a visit to his hospital despite being in perfectly good health.

"Kamijou-kun, what seems to be the matter?"

"Well, doctor, it's...about Mikoto."

Heaven Canceller laid down his pen and turned towards Touma, whom he gestured to sit.

The boy did so, and looked back outside, where they could see the Tokiwadai student sitting, throwing glances into the open door towards her step-brother, as though he could disappear at any moment.

"Ever since that incident, she's been...well, paranoid for me."

"Hrm, for instance?"

"If I'm not around her, or send her regular SMSs during school or at home, like every half-hour or so, she starts to freak out, sending me messages asking about where I am, or what happened. She frets whenever I trip over the sodacans and whatnot, or if I run into more serious trouble. Like, last night, she found me being chased by delinquents, as usual."

"You're the only person I know who would consider that normal."

Touma brushed off the doctor's attempt at humor, hissing: "Doc, she almost killed them!"

"..."

"I actually had to hold her, calm her down and drag her away before Anti-Skill got there!"

"Sounds like she should visit a psychiatrist. Though that would leave a mark on her record."

"Exactly, I don't want her getting flak for... anything, actually, but certainly not because of me."

"I daresay she'd disagree on that point."

"?"

"Think about it. She distances herself from you, causing you to feel guilt and respect her 'wish' by not asking her for help when you needed it – and don't say you didn't, young man, you almost died there.

Wouldn't you feel personally responsible for that in her situation?"

"So, she is doing this because..."

"Guilt. Which leads to the fear of a repetition. Hence her...extreme caution for your wellbeing."

"Isn't there something I can do? Without involving someone else?"

"Scientifically speaking, no. If she will not, or cannot, talk to you about it, or her friends, and speaking to professionals is out, she will need some other way to cope with this."

"...scientifically, huh?"

After the last Graviton Bombing, the two siblings met up again at a certain vending machine.

"You totally should've taken credit."

"What for? As long as everyone's fine, who cares about credit?"

"Well, I caught the perpetrator, so no more bombs."

"That's a relief."

"And as a reward, you're cooking my favorite tonight."

"Why are you rewarding yourself at my expense?"

"What do you mean 'expense'? It's the brother's privilege to treat his sister."

"Hai, hai, I'll be seeing you later, then."

"Hehe, cya."

"Touma?"

The week before Christmas, Mikoto was sitting in Touma's apartment in confusion as he moved things in his living-room/bed room around to make space. He also retrieved a sharp peeling knife from his kitchen as well as a first-aid kit.

"What are you doing?"

Before replying, he pulled her over to the middle of the room and sat her down, seating himself across from her. By this point, Mikoto was getting increasingly nervous, which showed itself in her breathing and on her face. Touma placed a hand on her shoulder.

"Hey, calm down," he started, "look, I get that you've been worried for me lately, and I'd be lying if I said that I didn't appreciate your care. But even you have to admit that it's getting a little out of hand." Mikoto looked away.

She knew what he was talking about. But...

"I know...I'm t-trying to take it easy, but then I think of all the things that could happen to you and—"

His finger stilled her lips, and she looked him in the eyes again.

"I get that," he reassured her, "That's why I've...thought of a little something."

Her face screwed up in confusion.

"You? Thinking?"

"Oh, har har."

He took up the peeler in his right hand, holding out his left palm.

"Let's make a pact."

"A...pact-?"

Cutting into his palm, Touma carved a circle centered beneath the gap between his ring and middle fingers, taking up as much of the palm as possible.

"! What are you doing?!"

Ignoring her, he finished it up, then held out the peeler to her.

"Here, you too."

"Huh?"

"Think of it as a contract, signed in blood."

"..."

Hesitantly, and eyeing his injured hand, she accepted the knife, and after an encouraging nod from Touma, mimicked his earlier action on her own hand. Seeing as how she was not as used to physical pain as him, she winced as she kept carving.

Only later would they realize that they had somehow managed to carve perfect circles. Albeit that hers was smaller due to her smaller hands.

When she was done, Touma took the bleeding hand and held it in his, intertwining their fingers. In this way, the two blood circles intersected each other.

He held their hands between them, consciously placing his right well away from the whole thing.

"...What now?"

Prompted by Mikoto's question, Touma took several deep breaths, going over his words before speaking. Seeing that it helped to calm him down, the girl mimicked him again, until they both fell into an unusual breathing rhythm, which caused small pricks of pain in random places across their bodies. The boy did not let that distract him, however.

Her eyes widened, as she took in the pledge that was spoken, one that promised an exchange of support, protection and reliance, whether physical, logical or emotional. It prompted her to repeat the pledge back to him.

For whatever reason, Imagine Breaker rang out several times during this exchange, and the painful prickling increased right before each time. Even so, as Mikoto finished, they both felt something that relaxed them. Though they did not know how, they could each feel the other in a way that did not correspond to the usual biologic senses of the body.

That day, Mikoto's irrational paranoia stopped, as she and Touma had gained a new sense that they respectively named 'Mikoto/Touma Sense'.

... a layer of onions, followed by a sweet apple! And with that, the grand majority of my world-building is done. The flashbacks certainly are. And next chapter, we'll jump right into the climax of the Level Upper Arc.

*This address is acceptable from children that are a little younger (less than ten years difference) than the addressee.

Read & Review, please!