My Brooding Girlfriend Was Reborn

One day, I received a letter from a parallel universe. It was signed by me. It said my girlfriend was going to kill me and that I had to be careful. But my girlfriend was already dead. I was the one who went to the police station to identify her body. The next day, I received another letter. It was in my own handwriting, just like the first. It said my girlfriend hadn't died at all. She was coming to kill me. I didn't believe it at first, but that night someone knocked on my door. Through the security camera, I saw a familiar, beautiful face. My dead girlfriend was smiling at the camera from outside my door, red lips, brown hair, and a long, flowing dress... Theme: Sincerity deserves sincerity