I'm a librarian who loves anime, manga, and reading a wide variety of genres.
I know it looks like manga, but this is actually a novel. Its events appear in episodes 11 to whatever of the original Fullmetal Alchemist anime, the ones with the two brothers (Russell and Fletcher) pretending to be Ed and Al.
I can't remember if I've read this before. I suspect not, although I definitely remember the anime episodes.
This should work for a card in the Kill Your Darlings game, although I won't decide yet which one.