It’s hard to understand from the translation but in the starting chapters Misaki said that even though he could’ve ran away from Haru and not gotten beaten up, he didn’t, because somewhere deep inside he had always been a masochist, but he didn’t actually want to admit it (and was pretty stubborn about it) in the entirety of volume 1 and 2 which is why he never communicated to Haru about it. I don’t see him as sad and pitiful or weak, because from the start he has been the one putting himself in these situations, even though he could’ve just cut Haru off from the start (not that it makes Haru’s actions any less horrible, but the only reason I can tolerate this dubcon and not others is because of the way Misaki constantly affirms himself to liking the freaky shit Haru does, and barely tries to even get away from him)
it seemed to me that showing haru's home life/family relations wasn't to explain away his violence as a product of that, but to show how little understanding/support he got and how it exacerbated his "me against the world" outlook which led to more violence. like he does have violent tendencies, and had them from the start, and they do cause problems for him, but he's not actually that aggressive unprovoked. to me, he's a very "my way", individualistic type of character in a way that clashes with the society he lives in where you're supposed to go along to get along and there's all these arbitrary rules and restrictions. vol.2 was all about this and how haru trying to succeed/command respect in societally expected ways (job hunting and the corporate job) overextends him and strains his relationship with misaki because his coping method is that socially unacceptable violence.
and that's what makes his relationship with misaki special, because he can be his abrasive self but also be met with support and understanding. but it's not like misaki is a complete pushover despite the masochism, and that's something that gives haru the impetus to change and want to make their relationship work, so he changes himself to accommodate misaki without changing himself completely in the ways that wider society demands. haru and misaki work/are compatible because they're both oddballs in ways that work out for their relationship. misaki was a masochist from the start, so there was no "conversion" process to show for him, just a sequence of realizations and self-acceptance and figuring out haru and what they wanted from each other.
haru is a selfish asshole sadist, but misaki isn't a pitiful weak helpless masochist uke. he's older and more established in life than haru, which is what gives them some stability to figure things out and so misaki isn't just getting pushed around by haru unless he wants to be, which is the conflict/back-and-forth of the first volume.
I do wish there was more of their consensual s&m scenes though it's still more than other series give.
So far I've only read vol 1, ngl I might still be drunk irl but I found the translation hard to follow and feel like there might potentially be more complex plot here lost in translation. That and/or it could have just been fleshed out more in general.
**Spoilers**
It felt like the author was trying to convey that a difficult home life made Kushiro a violent individual. I liked what seemed to be his realization of Misaki experiencing immense pleasure from gentle/vanilla sex and that he had maybe caused him to suffer a lot and feared repercussions from that, but that was only very briefly touched on then forgotten about. It would have been nice to see Misaki communicate that he liked it and it was consensual. We never seem to get Misaki's perspective on why the pain suddenly turned to pleasure for him, or why he seemed to seek out Kushiro for these beatings. But this yaoi is also rather old, back in the day plots did tend to be super shallow and we just kinda lived with it, but it irks me that it feels like the author was trying to go somewhere with this and then fell short.
The whole selfish asshole sadist x pitiful weak helpless masochist trope also annoys me but it is what it is. I like that they kept the S&M going even after their relationship was established but disliked that they cut out the sex scenes for it then, like you can see him being hit when it's dubcon but not when it's consensual lol ok.