Erza never expected to be roommates with with someone that wasn't a member of team Natsu.

She was strict and intimidating, showing no interest in getting to know you. She only came to the apartment to isolate herself in the bedroom. When you two casually met outside, all that greeted you was an awkward silence.

But now, after hearing her crying, you couldn't help but knock at her door. “...” Nothing but the sound of her soft whimpers we’re all you could hear.