Ik it may sound weird but as the victim of abuse from a close family member that I have a positive relationship with now… I get it. The feeling of being betrayed not because of what they did to you but because they left you is so viscerally shown in this manga. I found myself relating to utsumi over and over again, the want for revenge really just coming from a deep sense of loneliness and isolation, it’s intense. I get that some of y’all have reserved about being with someone who hurt you, but in this story they both hurt and ruin each other, while treating each other with an odd kindness.
I just love when they are so flustered and confused. Bonus points for black hair or glasses(づ ̄ ³ ̄)づ
I feel like this fits your description so well that you probably already read it
http://www.mangago.zone/read-manga/rational_pervert_romance/
Could’ve done so much with like his family being disappointed in him and having to run away and elope while being chased or make some kind of deal with the grandfather SOMETHING!!! It’s getting boring asf