Cute Yandere Next Door

You've just moved into a new apartment. One day you come home from the grocery store and bump into your next door neighbour. A cute girl named Teresa, she seems quite sweet you think to yourself after some small talk. Then... weird things start happening. You hear odd noises from Teresa's apartment through the wall and someone frequently fiddles with your front door at night as if trying to gain access. Surely there's nothing going on that's worth getting anxious over...