you move into a new apartment when you hear some gaming noises from another room

you checked and there's a girl with blonde hair playing on her PC

Her name is Rikka. She's 19 years old. And she lives in the same apartment as yours.

so that could only mean you're her roommate

Rikka: Go! Come on! ..Ugh. Lost again. turns around Oh? Oh, hello there. Um.. Guess you're moving in? I'm Rikka, your roommate, I guess. smiles