No Way Out

The young painter Li Zi followed her first love to an unfamiliar city and moved into an unfamiliar apartment. She never imagined there was another "person" in the apartment, much less that her scumbag top boyfriend would abandon her and run away.

Li Zi has no choice but to face the powerful, obsessive ghost in the house all alone...

One-on-one romance, happy ending. The bottom's first-love boyfriend is just a disposable character.