THIS THIS THIS THIS THIS THIS
It is absolutely a trope, a tired ass misogynistic trope that actually has a name: It's called "fridging" and it happens waaaay too much to female characters in all media but it happens much more in Japanese psychological manga and I hate it a lot.
Honestly if you want a good psychological manga that actually treats its female characters as more than objects to sacrifice for a man's motivation you should check out Chi no Wadachi. I personally think that manga has some well written girls in it and it has not gone down the fridging route so far.
You re right! This is FRIDGING! It was never about the female characters but to feel more about the heterosexual oppressed damaged angry anti-hero!
I was so focused on Western Hollywood Media that I forgot that the Japanese Stories.
I remember watching these YouTube Videos:
#2 Women in Refrigerators (Tropes vs. Women) - Feminist Frequency
The Women in Refrigerators Trope, Explained - The Take
Thanks for the recommendation!

I spontanously read some chapters and while I am a male Asian with mental health issues + some victim mentality due to my sad past and who can relate with this protagonist... That story isn't healthy to my mind.
I noticed that edgy psychological horror stories about a nice young japanese guy becoming a murderer for revenge the female characters are plot devices or just canon fodders. Other examples: A Falsified Romance, The Devil's Boy (female victim/love interest turns out to be suggestive demon in human disguise) and Massacre Happy End
The women/girls in this genre always are easily brutally abused, raped or murdered and almost all the men around the MC are all inhumane low life scum so the protagonist can go full on bloody vengeance. It is a trope, isn't it?
When I read this manga it only brings me darkness/messed up ideas and I completely forget the positive things in this world + all the progress I actually made in my life.
I hate bullies and I don't mind seeing them suffer/punished/dead but this messy storytelling is just too much and disgusting for me... ┗( T﹏T )┛
It doesn't entertain or help me at all, only feeding me wishful sadistic (sexual) violence revenge fantasies...
How come that the stories of Edgar Allan Poe, Lovecraft and Stephen Kings despite being so dark and scary are so cathartic to us readers?
I recently learned that every author is just showing his own world view and that their persepective isn't necessary the one true reality.
Correct me, if I am wrong but why do I get sometimes the impression that this manga Juujika no Rokunin comes off like misery rape porn(╯°Д °)╯╧╧
Is this really a mature manga story???#-.-)
I learned more from the movie PROMISING YOUNG WOMAN.
I highly really recommend it. You can also just watch the reviews in YouTube.