Alright, responding to reviews is a lot harder here than what I'm used to but I'll give it my best shot.

Whether or not Rin can use UBW is intentionally not revealed yet, sorry. It will be settled by the end of the series.

Rin turning into EMIYA and not Ishtar is indeed for plot reasons, it allows for more stuff to happen with Shirou reacting to that spirit.

No Ascensions for Rin, sorry.

Chapter Four

Shirou found himself breathing heavily as Rin entered the dojo. He had diligently prepared the dojo as requested, and Rin had been equally faithful in fulfilling her part. She had followed his order, and put on a naked apron.

The apron was not something he recognized. He certainly didn't own such a frilly white apron that covered so much of both the chest and legs. He supposed she must have made it with projection. Her face was flushed bright red, and she was conspicuously standing with her front always facing him, so he assumed she was going for a strategy of covering as much skin as possible.

Still... it made him feel so warm inside. Rin had followed his orders. She was right now wearing nothing but an apron, because her Master had ordered her to and she had decided to obey. Something about that felt so magical that he wondered if it was some kind of inherent desire all men must possess.

That young girl he had seen in his dreams was right. Being a good Master really was a virtuous pursuit. Otherwise it surely wouldn't feel this good. Yes, it felt just as good as it did when he rescued someone. For a brief time, the guilt receeded.

"...Exactly how long are you going to stare at me?" Rin demanded. She had her hands behind her back, which combined with her deep blush to make her look adorably vulnerable. He wanted to reach out and take her so badly that it hurt to hold back.

But he did. This was training time. A good Master wouldn't risk their Servant's safety by neglecting their training.

"Sorry, sorry." Shirou said. "Let's get started then. Why don't you begin by giving me a summary of your abilities?"

Rin sighed. He honestly couldn't tell if she was happy right now, he couldn't tell if she could tell either, but regardless she was clearly having trouble trying to look calm. "Yes, M-master." She stuttered over that word for the first time, after saying it so confidently up until now. The naked apron must have bee n shaking her demeanour. "F-for the combat presentation is it alright if I summon my battle gear?"

"Absolutely not." Shirou said, and her shoulders fell a little.

"...Of course not." Rin said. Her face was clouded with emotions. "Then, without further ado. To begin with, I should start off by saying that I don't know the identity of the heroic spirit that I'm bonded with."

"Is that usual?"

"It's not like we take surveys of previous Servants, but I would think that most people would be able to tell who a Servant was by recognizing their Noble Phantasm. For example, if I was able to summon Excalibur it wouldn't be hard to tell that I was bonded with King Arthur." Rin explained. The deeper into the explanation she got, the more in control of herself that she started to look.

"And you don't recognize the swords that you summoned?" Shirou asked. He was sure that he'd heard her recognize Hrunting.

"No, I recognize each and every one of them, and I know the history of them all." Rin said. She crossed her arms over her chest, looking thoughtful. "The problem is, there's too many of them. And none of them register as something belonging to the Heroic Spirit I'm connected to. Rather, they're all just cheap copies that I make on the fly."

Shirou remembered the pair of glorious twin swords that she had summoned, and felt a little insulted on their behalf.

"It's a technique similar to Gradiation Air." Rin continued, caught up in her explanation. "I don't know what kind of freak you would have to be to practice such a useless technique so much that it becomes something capable of copying Noble Phantasms, but it's what I have. Of course, the trade-off for so much variety is a loss in ability. Each copy I can make is inferior by at least a rank from it's true self."

"So that's how it is." Shirou said. To him, that sounded like a wonderful way of fighting, but he understood Rin's trepidation. "I see. Then, there's something else I wanted to ask about. Aren't you supposed to be an archer?" The only things he had ever seen her use were swords.

"You're telling me." Rin said. She put a hand on her forehead, in exasperation. "Before you became my Master, I had a much looser grasp on my abilities. I would say I had access to only a quarter of the Noble Phantasm blueprints that I now have in my mind. I don't know if calling this a Noble Phantasm is fair, but I do have a bow."

In her hands, a large black bow appeared. Shirou admired it for a moment. It wasn't anything like the Japanese style bow that he was used to, but he thought that he had enough experience to recognize a well made tool when he saw one.

"This appears to be why I'm an Archer." Rin said, summoning an arrow into her free hand. She notched it against the bow string. "With this, I think I would be able to accurately hit a target from the other side of the city."

Shirou's heart rate tripped. By turning to pull the arrow along the string, she exposed her backside to him completely. As ordered, she was wearing nothing beneath the apron at all. He could see every bit of her pale skin. Being the Master of such a beautiful girl was a wonderful thing.

"But, considering how strong the two other Servants we've seen have been, I don't think this much firepower would do much more than distract. In fact – AH!"

She'd noticed.

Rin jumped, almost falling down in her mad scramble to turn away from him. The blush returned, deeper and larger than before.

He'd expected her to look mad. But while she was embarrassed, there was something else there as well. Satisfaction? Warmth? Something on that level.

"A-anyways Master, I'm afraid I'm no good as an Archer." Rin finished, lamely.

Shirou shook his head vigorously. "No, Rin. That's not true at all."

"Hmm?"

"Your mistake is thinking that those are the only arrows you have access to." Shirou said. Since it was his turn to lecture, he let himself feel a little proud. "Look, summon that sword from last night."

"Hrunting?" Rin asked. When he nodded, she did as ordered and brought the blade out for his inspection.

"This sword always follows a perfect swing to hit it's target... don't you think this would be better used as a long ranged weapon?" Shirou asked.

"I don't think it's that simple." Rin complained.

"No, for you it is." Shirou said. He smiled at her, which for some reason seemed to make her even more hesitant. "Go ahead, give it a try."

It wasn't an instant fix, but with a lot of effort and several tries Rin was able to pull it off. The sword was stretched out into an arrow, one that would always fly towards it's target. And it was still a Noble Phantasm, with all of the conceptual weight that implied.

"Amazing! Having a Master is the best!" Rin said. She didn't seem aware of how happy that made him to hear. No doubt she was talking strictly in terms of combat benefits, but he couldn't help but feel like his entire spirit had been lifted up. One day, he hoped she would say so more seriously.

Of course, there was no way to practice with them in this tiny little dojo, but Rin managed to successfully trace a few other Noble Phantasms and turn them into arrows. One that she was particularly proud of was a remodelling of Caldabolg, although he quietly felt that there was still a little more potential there.

"Then, there's only one thing left to confirm, Master." Rin said. She looked serious again. "Last night... were you able to use my Noble Phantasm?"

"Is that strange?" Shirou asked. After all, she was his Servant. He felt like using the things she made was somehow second nature to him.

"...I don't know." Rin said. "I have never heard of anything like that before. Honestly, in the first place sending a Master into a battle is already a stupid idea. It could just be that nobody before us was ever desperate enough to try."

"Well, at any rate, let's get some lunch." Shirou said. He felt a grumbling in his stomach already. "After we eat, we can do that lesson on magic that you talked about."

"Right, right." Rin said, nodding. She didn't seem to want to show it, but he had no doubt that she was just as hungry right now as he was. All that tracing of Noble Phantasms was hungry work.

The walls she had raised around herself were lowering wonderfully. Slowly, over the course of their training session, she had stopped trying to hide herself from him. Now, she was even walking a little in front of him, totally aware that he was eyeing her as they travelled towards the kitchen.

"Hey, Master? Can I at least take this thing off while we're eating?"

Shirou shook his head. Then he relented a little. ""You can. But you can't put anything else on if you do remove it."

Her fist swung for his head. He blocked it, confused. He was just doing his best to be a good Master, so he thought that she should be at least a little grateful.

X X X

Rin fumed.

That idiot! That absolute idiot!

It would be harder to pick something that she wasn't mad at right now than the reverse.

For starters, she had just finished teaching her Master his first ever proper magic lesson, and she'd been so horrified about what he'd been doing that she'd forgotten about her naked apron situation for at least an hour. She'd corrected him of course, and given him many lectures about what he should and shouldn't be doing, but it made her furious to think how close he'd been putting himself to death every day. And if he'd done that in the middle of the Grail War, with all those extra stressors, it might have been the end of both of them.

The second reason she was so angry, had to do with her current situation. Fixing his mistakes had taken most of the rest of the day, and then she had gone back into hiding to avoid Fujimura. When that was over, she'd expected him to finally relent and remove his naked apron order.

Which, in a way, he had.

Her Master, with that same damn straight face, had told her that he was going to be bathing and it was going to be her job to wash his back.

And the third and absolutely most vital reason that she was so angry, was that at some point today she had found herself enjoying herself.

It made a furious blush rise to her cheeks just admitting it. It was beyond idiotic of her. But she, magus of the Tohsaka bloodline, had been enjoying being forced to wear a naked apron and being ordered about for the entire day.

And that was the most unforgivable thing of all.

Even now, she was excited more than she was upset. She'd wrapped a towel around herself, as her only shield of modesty and even that was more than she had been wearing for the rest of the day. On the other side of that door, was her Master. Bathing. A naked man, ready for her.

There's no reason she should be so happy about any of this!

...No, she had to admit to herself at least that she was a healthy young woman. Of course, she was curious about men. Who wouldn't be? So sure, it shouldn't be too much of a surprise that she was interested in getting the chance to see one up close. To do something shameless like this, while she was young.

But she should have been angry about being forced to do it. And she wasn't. She was... happy, that her Master had ordered her to serve him like this.

She wasn't sure when she did it, but at some point she pushed the door open. It creaked slowly, revealing the figure she had come there to see inch by inch.

Shirou Emiya, her Master, was a well-muscled man. His gaze could be strict, but his nature was soft and caring. I-it wasn't like she thought he was particularly good looking or anything, but as long as she was going to be doing this with someone she was glad it was someone that wasn't abhorrence to look at.

"Rin. You took a while." He said. His back was to her, so she couldn't see much of his expression, but he sounded happy that she had come.

Her body got even warmer, for some reason. "Y-yeah, well after giving such an unreasonable order you have no right to complain about how long it took me to arrive here."

"I don't see what was unreasonable about it." He said. She could tell he was frowning. Damn it, she wanted to kill that stupid little girl from his dreams! He'd told her about her, and even knowing the woman was imaginary, Rin hated her with all of her being. Like they were destined enemies.

"...Whatever. I'm getting started." Rin said. It was easier with his back to her. Although she was the woman, she somehow felt less exposed.

Rin knelt down, and grabbed the cloth behind him. She took her time, running it along his bare back delicately and slowly. There was less than an inch of material between her hands and his bare skin.

Rin... went very slowly. Savoured every second.

Her head and body grew hotter and hotter with every extra inch of him that she rubbed down. Acting like such a meek slave –

Damn it, she was getting turned on.

There was no way she could deny it anymore. If the towel came off, he would be able to see clearly just how absolutely soaked that she was.

And... if he did take the towel off... she'd have to make him take responsibility, wouldn't she? Would that be so bad? Wasn't it natural for a Master to calm down this raging part of her, by any means necessary?

"Rin." The simple word startled her. "...Are you going to clean the front?"

A question. Not an order. Maybe she should do it. To show some thanks for –

Every natural urge in her body wanted her to go through with it. But that exact moment, she remembered something that her father had said to her.

Rin. A Tohsaka does not serve. Any Tohsaka who accepts a Master, is not fit to be a part of our bloodline.

"IDIOT!"

She screamed the words at the top of her lungs, and dashed for the door. She hadn't been yelling at her Master. She'd been yelling at herself. It was bad enough that she'd bonded him in the first place. Now she was letting him boss her around like that? Now she was getting excited at the idea of being taken by him?

That was too far. Her pride wouldn't allow it.

She stumbled back into her room, completely naked. She wasn't sure when she'd lost the towel. With a quick twist of her hand she projected a block of wood to bar the door.

No matter what, she couldn't allow herself to submit. She just couldn't. No matter how good it had felt.

And here we have Shirou pushing his luck a little and Rin not being able/willing to take it. It may feel a little overly dramatic, but I felt that it was necessary to give their relationship some early conflict. Next chapter will feature Rin and Shirou's POV on what happened here along with... let's just say another surprise.