Half and Half (Oblivious!Eren x Reader x Slight!Yandere Levi)

Brainless Brat

After a couple days had passed, Eren wanted to read more books in the library to gain more knowledge. You helped him pronounce words and write them. Eren's English was improving little by little. He was able to grasp onto the comprehension of a human lifestyle. He had told you many times that he desired to explore the world outside the walls with you. His learning skills have enhanced and many recruits were gradually accepting him as one of their own. As for Reiner, he was only able to walk outside his cell for a certain minimum of time, so there was a limit. And during his spare time, Reiner would teach Eren how to do mathematics and counting. He was very poor at it, then again, he did not give up on knowledge. His hunger for curiosity was only the beginning. No end would come to it. There were rare times when Eren walked to the library alone. But that no longer happened because he would always find books that would explain human biology. You forbid Eren to read those books, feeling that Eren was a little "too young" to pick up such books.

"There are 24 hours a day, 7 days a week, 12 months or 365 days a year..... Right?" Eren asked.

"Yeah, you're right." You nodded.

"Three walls that protect the people: Maria, Sina, and Rose." Eren named them off from memory.

"Yep."

"TItans have no digestive system. They are only active during the day. They eat humans, nothing else."

"Correct."

"Am I.... Getting smarter?" Eren smiled innocently, shrugging his shoulders up in excitement.

"... Yeah..." You responded.

"I'm like you now! I can understand you more! This is great!" Eren takes your hands, cheering with happiness.

"I'm glad you are, Eren." You laughed shortly after his brief celebration.

Seeing Eren like this made you feel different. It was as if Eren was never a titan from the beginning. Just a normal human being like you. But it was something that didn't bother you. Eren can understand the human language and have knowledge on how to live a human life. Suddenly, your thoughts were withered away when you hear piano music playing outside the library. You paused for a moment to verify that you weren't imagining things. Eren had also stopped as well. You knew that there was a piano found by Hanji when they first cleaned up HQ. As far as you know, no one was at least an amatuer at playing the piano. Never once have you ever heard of good music from the piano.

"What's that sound, (First)?" Eren asked.

"It's.... It's a piano playing..." You replied, standing up.

"Piano? What's a... Piano?" Eren wondered.

"It's an instrument in which people play to make music." You responded, your eyes never leaving the exit of the library room.

Who's playing it?

"Must be Moblit or someone. We should continue, Eren. Let's not get sidetracked." You sighed.

"Yes!" Eren nodded as he began skimming through pages.

Yet, the music was growing louder and louder, creating crescendo throughout the hallways outside the library. And hell yes, it was annoying the crap out of you. You were practically losing focus. Eren never noticed, but he was also losing focus on reading and paid attention to the slow tempo of the rhythm. You were losing patience by the minute. And out of nowhere, the piano began to roar, random notes created an unpleasant sound, as if an unprofessional or a beginner was playing the piano freestyle. Your eyebrow twitched, causing you to close your book and stand from your chair.

"Someone's messing with that old piano...." You thought.

"Eren, you stay here and study the book. I'm going to the piano room to check." You told him.