First of all, the synopsis above is pretty lackluster so let me explain what this manga really is about :
The story takes place in the XVIIth century in Central Europe (basically somewhere between Poland and Germany). The protestants are getting leverage in the region, which is not appreciated by the catholic church. This is the new age of inquisition, and companies all around Europe go on a witch hunt.
We follow here the story of Ella Kowlosky, a young girl who gets sent to a monastery run by the order of the Claustrum. The goal of the monastery is to transform witches' daughters into righteous nuns.
story is great because it is basically the tale of a few people rising against oppression. It is a story about determination, and how hard it is not to lose yourself when all your liberties are taken away.
The main characters all have different personalities that complement each other and make for a very credible story. I really rooted for all these characters, felt their sorrow and their joys, which are really well conveyed.
Another plus for this manga is the ending (spoiler free don't worry) : it is really hard to know who will win in the end : will it be the order ? will it be Ella ? both ? none ? The author really did a great job to both make the ending and the hardships Ella gets through (or not ? :s ) really important.
It has basically climbed to the top spot in my favorite mangas, must read !