Okay I'm.. Trying here, but this manga.
MC acts like this happened a year ago. It's like his road to understanding and coping with all of this ONLY started AFTER he spent a copious amount of time in prison.
Secondly the familial shame only runs one way.
I get I'm not Japanese but I find it EXTREMELY hard to believe that everyone would just be looking down on him and HIS family for murder, but not also considering the situation in which it was done.
Everyone seems to know exactly what happened and why.
He was a teacher, she was his VERY minor student, and he had a daughter of his own.
There's no circumstance where what HE did isn't at LEAST as bad as what the brother did.
Everyone talks as if what happened to his sister was some minor incident and he flew off the handle and murdered some pillar of the community.
It's extremely fucking odd this manga barely acknowledges that what happened to his sister was absolutely not acceptable.