This is one of those yuri titles that is SO CLOSE to making a nuanced point about sexuality, objectification of girls, and the cycle of sexual violence. You've got Hotaru. Hotaru is neglected by her father her entire life and has self-esteem in the negative. She hits puberty and the only positive attention she gets from anyone besides Yuma is from men who view her as an object. Our girl's gay (maybe bi, probably gay) but she's only really worth anything to anyone if she performs her role as an object to the gratification of men. Starting with Fujiwara (I assume), the regular objectification escalates into violence. And that objectification and sexual violence gets reenacted on Yuma cause Hotaru doesn't know how to have a relationship. And you've got Yuma, essentially a late-bloomer who becomes a victim of this violence but has a complicated relationship with it because it's with her friend who she has always viewed as more than a friend (unconsciously or otherwise). Hotaru first experiences self-worth and sex through passive objectification and violence and she continues this cycle this time in an active role with Yuma with some level of self-awareness but always believing that this behavior in this context is safe.
These are all facts of the story and they are all very interesting and would make for a fascinating exploration. Unfortunately, this is not what this story is about. Hotaru is stripped of all nuance and becomes basically a 1D hentai character. Yuma is under-developed. Takeda and Fujiwara are fleshed out just the amount the need to be in a story that should be about the devastating relationship between Hotaru and Yuma. I can see why people absolutely hate this manga/anime because when you take the story at face-value, it's about vile people hurting other people for no reason. But the thing is that there IS a reason, they're complicated and grey reasons, but they are reasons and they do exist in the real world. I think that's what really fascinates me about this manga. Somewhere in one of the extras, the mangaka says that the original plan was to do this with married adults, and I can see how this story would have worked if they would have had the room to explore the dynamics that they set up so well.
You also see this in Citrus. Both of these titles deserved better.