Why because they're blood related? You don't owe them shit just for being born. If they're a toxic presence in your life, family or not, you cut them out.
She even isn't blood related. She is his step-sis. Their parents married, her original big-bro died, and her dad supposedly married with a mom with a male kid to give her a new brother to "fix her".
Or Nyanta to pomeko?
MC there had childhood friend, got betrayed by her to a certain degree, found a silent bookworm friend in library, got betrayed again, and then few other girls, his step-sister tattled on him to his step-mom who of course didn't believe him, and they all wondered why MC became a "human interaction hating machine". Girls gone after him again, behaving like they did nothing bad, even thou dude was abused socially even accused of being a SA offender, to the point in most mangas he would log out of life, wondering why the fuck can't he just forget the past and freaking love them back.
But then again all this betrayal and hurting MC gone through with them, kinda makes it far different that this manga.
With the exception of the FML liking the MC and some other stuff, the setting reminds me of another series where the MC was pretty much abused by his mom, sister, and like 3 other girls he knew in school and are trying to get him to like them again.
But yeah, I feel like the MC is too beta and is just going to forgive the girls for treating him like trash for no reason.
If its Nyanta to pomeko, then in my eyes its to different, if its the one mentioned by rluka, then I didn't read it, and seeing how theres no chapters on this site, I probably won't read it at all
, thus can't comment much.