Actually, I never did. My sister was an avid reader, but I developed a case of 'meh' and stayed away (save for the occasional times I had to help her with a tie-in game or two). Was still forced to watch one or two movies of it though.
Sorry to bring in the news, but this one just got updated again not too long ago. I'm not terribly interested in the game, so feel free to take your time to update it. 敗戦隷姫エルネア to v25.04.23