He and she had made a promise to keep each other deep in their hearts forever and never forget them.
Later, he turned into a ghost and deeply remembered everything related to Yue Huaye; she was still alive, but she forgot about him.
Even when he appeared in front of her, she didn't remember anything related to him.
She forgot herself, her name, and who she was. He became a stranger in her world.
Forever strangers.
Conception:
I watch it every day, I hope there will be extras