The ratio of trauma vs healing is completely off in this manga, where it is about 80% trauma and 20% semi-healing. For a good trauma/healing story, those numbers should be reversed or at least 50-50. As it stands, it is just a lot of bloody violence with very little character growth and a forced "happy ending" that reads more like battered wife syndrome than actual love.
I do find the characters themselves interesting, but the author needed to portray a lot more of the post-make-up reconciliation and difficulties. Watakabe should have had more struggles and inner turmoil leading to an obvious (aka show it to the readers!) paradigm shift followed by an equally painful and much longer time reforming himself and apologizing/making it up to Hazuki. I mean, what's going to happen if Hazuki gets a job in another city post graduation? I don't feel like at any point in the manga Watakabe resolved his issues of control, so they're going to be a miserable couple in the future if Hazuki ever gets a life independent of Watakabe. (Well, I guess in the author's mind, Hazuki will make a cute housewife or something...)
If you get past all the rape and abuse... who are you kidding? There's no getting past the rape and abuse here, and I don't know how some people can. This story's core is rape and abuse. Without it, it'd be a happy story of love, sure, but that would be a whole other story with whole other characters--not this story. This isn't your typical BL "forced love" or dub-con--it's 100% violence and abuse and should be read as such.
The only way to redeem this story is to rewrite it. If you want this sort of plot but done infinitely better, go read Sayounara, to Kimi wa Te o Futta, which is an incredible manga.