Oh yes, that's right. The amnesia after waking up. He will try to make her remember, but he fails. He gives up, and after some time passes, something triggers her memories, and she reunites with him.
Yes, i love that it has romance. Ok, let me guess how this turns out. They fall in love while working together. Of course, they have obvious concerns because one's alive and the other a ghost. But here's the twist, she's not dead, just in a coma. She wakes up at the end, and they live happily ever after. That's usually how it goes.