Overprotective: AOT/KNB Crossover [Reader x Eren]

Chapter 1: The Transfer Student

~from (y/n)'s POV~
You hesitated at the door. I've got the right apartment...I think...Your eyes quickly scanned the note in your hand before eyeing the numbers on the door. Yeah, they're the same...but I'm kind of scared to knock...
Before you could make up your mind, the door swung open and you squeaked, jumping slightly. "If you're coming in, come in. Don't just wait outside like a freaking idiot," said the apartment's tenant before walking back inside.
Taking a second to collect yourself, you grabbed your suitcase and went in, shutting the door behind you. "Um, hello, I'm..." You stopped after you realized that he wasn't even in the room anymore. Ugh. Why is it like this already? Sighing as you resolved yourself to the new situation, you grabbed your suitcase again and began dragging it along with you, figuring that you'd find your room soon enough.
However, the first door you tried was a bathroom, and the second one a closet.
The next one, for sure...
Only, when you turned the knock, it stuck. Huh? It's locked? You jiggled the knob for a second before the door swung inward all of a sudden (causing you to freak out again) and you came face to face with the boy from earlier. "Would you stop doing that? It's annoying," he snapped, moving to slam the door, but you came back to your senses quickly enough to shove your foot in the door.
"Hey, wait, Levi-"
"Don't call me that," he said, glaring at you.
You so desperately wanted to take a step back, but you forced yourself to hang in there. "Then...Heichou?"
"Definitely don't call me that," he said, looking even more menacing.
"T-then what should I call you?" you said quietly, trying not to break down sobbing. You see, it wasn't that you got really emotional or anything. Nope, truth be told, you are just a total scaredy-cat, and Levi is threat-level high!
"Damn it," he muttered. "Just call me Levi."
Is this guy crazy? You ignored the thought that was sure to incite sudden death and instead gathered up all of your courage. "Um, Levi-"
"What do you want now?" he asked, giving you another evil look.
Be strong, (y/n)! "Uhhh, I was just...trying to find...my room." Yes! The words! There they are!
Not at all impressed, Levi just crossed his arms. "What room?"
"Ummm, because I'm...staying here...for a while. You know...because-"
"I already know why I have to deal with a kid like you," Levi said, scowling. "But there is no room. My apartment isn't all that big, you know."
Is he always such a jerk? you wondered, but you were still too scared to be angry or offended.
"You can take the couch," he said, and in your shock, you took a step back and accidentally let the door close. You heard the lock immediately engage and took that as a sign that Levi no longer wanted to speak with you.
Tired, scared, and morally deflated, you dragged your suitcase back the way you came and collapsed on the couch. You'd already been considerably brave in simply talking to Levi, and that had seemed to exhaust all of your energy. Plus, you'd had a long train ride just to get here. A little bit of sleep couldn't hurt...
***
You woke up the next day feeling...well, still fairly tired. You were going to work up the courage to ask Levi what he had for breakfast when you realized that he was gone.
Where'd he go? you wondered, before it slowly dawned on you...
Today was Monday.
On Monday, there is school.
Levi goes to school.
YOU GO TO SCHOOL. Or rather, you SHOULD BE AT SCHOOL RIGHT NOW!!
Ditching breakfast, you ran all the way to your new school and only managed to get lost four times on the way.
Of course, much of the confusion could have been avoided if you would've just asked someone for directions...
...but you were too scared.
You'd always been this way, for some reason - too shy for your own good. You didn't mind being invisible. Life was less scary that way.
***
You went to the office, where an aide gave you your schedule and told you to go to advisory. You were also told that until you adjust, you were put in Levi's advisory, even though he was one grade above you, so you'd see at least on familiar face that you could ask for help.
Like I'd ask him! He's so scary!
But then again...so was everyone else.
***
You swallowed, shaking slightly. You were standing in front of your advisory, all seniors in high school, and the teacher had just asked you to introduce yourself.
"I'm (y/n) Ackerman and...umm..." You were trembling - why are they all staring at me! It's so scary! - and trying to endure it. "I'm transferring here to...um..." You quickly bowed. "Please take care of me!" you said quickly before practically running to your seat.
The way you said it though made it sound more like Please ignore my existence!
"Ackerman? Hey, Levi. Your last name is Ackerman, right?" a male classmate asked, turning to Levi, and you squeezed your eyes shut. hoping Levi didn't look at you.
"What's it to you, freak?" Yep, that was Levi for you.
"Are you guys related?"
There was a moment of silence. "No way. Who'd want to be related to that loser?" Levi replied shutting his notebook.
Despite you wanting to remain invisible and realizing that it would be hard to remain so if your relationship with Levi was discovered, part of you was hurt inside.
Well, it's not a big deal. I only have this one class with Levi, and I can avoid him for the rest of the day...
As though reading your thoughts, he turned to glare at you. Eek! He's still terrifying!
Just then, the bell rang, saving you from another death stare, and you rushed out of the classroom.