I wrote this story ages ago and have decided to publish it for your entertainment.
You are a very shy and quiet girl, but can be sarcastic and funny.
Hanji is your best friend and your Eren's biological sister and is friends with Erwin, Levi and Hanji but you don't know Levi or Erwin.
But whilst waiting for your friend Hanji with Eren and unbeknownst to you he was waiting for Levi and Erwin. All three turn and Eren finds out you know Hanji and you find out they already know each other.
Sorry if description isn't very good