I like it! I bounced off the English translation really hard, because as translated, imo it just sounded like kinda basic and childish writing? (There are only three volumes translated.) I don’t know if the Japanese is that more mature than the English is (…when the heroine keeps 悲鳴をあげた-screaming over and over in the 7th chapter, that doesn’t suggest the strongest writing, even if the situation calls for it; but then again the kanji choice is rather interesting in some places, and the language is quite descriptive in other respects). But, even if a Japanese speaker would say it is childish, it gives me a better chance of absorbing vocabulary when the same vocabulary is used over and over, so while it may lack “literary merit,” it’s perfect for me as a second language learner. Overall, it’s better if I don’t notice the construction flaws so I can enjoy the story. (In English, I’m really picky.) Also, the anime doesn’t stay in that childish starting place, so I don’t think the book will either. I have a strong suspicion that the writing will grow improve and stronger as Youko grows as a character. The book is different enough from the anime that I feel like I am gaining more understanding of the world and characters from it. There’s plenty of extra internal point-of-view-dependent information that the anime couldn’t convey in detail, like who Youko’s parents are and what her relationship with them was like.
It’s… What I love about this story is that it looks like girl standard wish fulfillment, and heavily draws on those classic shojo isekai tropes at first (re: Fushigi Yuugi, Inuyasha, Rayearth, etc. - there’s probably others), but it isn’t really. You bite into it thinking the plot is going to be foolish light fluff, but it’s not: it’s actually substantive and bitter with a complex aftertaste.
Tl;dr: I’m enjoying it greatly, and that’s the most important thing, and that’s what keeps me reading.
As a warning, the first chapter is really difficult as it dumps you into the middle of Youko’s recurring nightmare and the description uses somewhat uncommon words and is difficult to get through. You can probably skip it. I also took some time to label the map at the beginning of the book so I wouldn’t be lost when those names are referred to later…the meanings of some of the kanji are kind of obscure though. After that, you continue reading through her schoolday and then the “abduction/rescue” begins, and the description is more evenly spread out and the text is much more straightforward and easy to plow through.