There is NTR in the core route of the game, but you can still end up saving her. But it is not totally avoidable.
Based on the comments and reviews, it seems like people want something different than what the game is, it is what it is, if people don't like reading, or transformation, or NTR, then they probably will not like the game.
It is not meant to be a visual novel, it is meant to just be a reading-oriented book with some pictures to kind of illustrate some parts of the writing. And if people don't like that I totally get it, most content on this site is VNs and animated games so if people don't like this sort of content at least there are a lot of options. This is just the kind of stuff that I like and I get if it's not for everyone.