Thank you for the encouraging comments, everyone!
(And sorry about any broken hearts.)
I'm reminded of the theme that turns up a lot in French, Irish and Galician folktales, where a close couple are cursed in some way to only both be together for a few moments at dawn and dusk, generally because one or both are shapeshifted.
I wish I could say the resemblance was intentional, but unfortunately I'm not that knowledgeable about folklore.
But that's an awesome fic idea for someone to write!
And how can you write this fast?
Actually, I've discovered that having an unfinished fanfic waiting helps me finish my translation homework a lot faster than I usually do. If I promise myself that I can keep writing once I've finished, say, my law translation assignment, I magically manage to translate the whole thing really quickly, and this leaves me plenty of time to write.
(Well, I also neglect other things I should be doing, but let's not talk about that...)