Although you are a girl, your garb gives no real indication of your gender. You haven't filled out enough for your body to stand out, and you aren't pretty enough to gain admirers. In fact, with the way you appear now, you seem more like a grubby, waifish boy. But that didn't really matter when signing up to be an adventurer; however, ability did. You have no real aptitude for magic, you are too lean to be a knight, and while your archery is passable as an amateur hunter, if the prey were monsters, you would not stand a chance. Still, you had to sign up for something, if only to provide some relief for your parents and younger siblings.
You decide to go over and check out the various training paths available while scouting out the different sign-up booths. You make it halfway across the square before you suddenly stop in your tracks. Everyone around you continues on about their daily business, but you definitely feel it.
You see, you don't really have any abilities, but you do have a rather random sensibility. That is, you were abnormally aware of someone staring at you. You wouldn't even have to know the person was there, or even spot them, but if you were the one they were focused on, you could somehow tell, especially if they were more powerful than you. You honed it while tramping through the woods alone desperately trying to find small prey or edible plants to keep your family from starving due to poor harvests. It told you when a predator was stalking the same prey as you, or worse, was stalking you. It kept you alive.
Someone was observing the people in the square. None of them knew it, but you did. And boy, were they powerful. It was like having a full-on dragon eyeing you, it made you so nervous. So, you did what came natural. You promptly turned around, edged out of the square, and skedaddled.
After running through a maze of alleyways, you finally stop in a deserted one to catch your breath. You needed to sign up for the adventurers academy, but not while that scary observer was there. Maybe you could sneak back later and check it out. Just when you were about to take a breath and walk away, you heard it.
"Oh my, I thought all the recruits this year were worthless, but it looks like someone has potential," a husky voice whispers in your ear. You freeze immediately, not only because of the voice, but because you only felt it at that moment. The gaze which terrified you in the square appeared out of nowhere...and was now locked entirely on you. You know instinctively there is no escape, so you cautiously turn around to face the speaker.
A wiry person in close-fitting clothes and a hooded cloak which hides most of their face is smiling at you, a smile that is clearly predatory. You suspect from the timbre of the voice that it is a woman, but technically the form could be that of a petite man as well. While you are shaking in your boots, nothing about the stranger's actual appearance is intimidating; in fact, they would be overlooked almost everywhere because they seemed...excessively ordinary. But you could feel it, they were anything but ordinary.
"So forgettable," the woman(?) smirks as she eyes you up and down, circling you. "And so aware. It is like you were born to it."
"To what?" you blurt out before you can stop yourself. The woman's sneer grows wider.
"To be an assassin, of course," the woman replies easily. "You were going to sign up for the adventurer's academy, right?"
"The academy...doesn't have a course for assassins!" you retort, confused and astounded. There was no way such a reputable place would train assassins...right?
"They don't call it that, of course, silly!" the woman snickers at your naivete. "Take the 'rogue' track, it's basically a catchall for those with no useful abilities, but don't worry, little one, I've taken a personal interest in you. I'll be your mentor; you'd be wasted in the general courses. Hurry up, I don't like to be kept waiting!"