holy underrated gem. super fascinating portrayal of trauma and abuse.
and she did try to escape, but her mother hunted her down and tore down any chance she had. she doesnt have any other family she can really run to (grandma is in close contact with mom and dad is a major pushover), her mother is restricting her contact with the world, not to mention shes been broken down and conditioned for so long.
theres something called learned helplessness, if you teach a puppy that nothing they can do will stop them from being shocked, they will eventually stop trying and accept it. hikari was taught by her mother that if she disobeyed or tried to escape she would be severely beaten, berated, abused, and tortured. unsurprisingly, this fucks up the brain!
because she felt she had no other option (and at this point, despite loving her, im not even sure she was fully seeing her mother as "human" but instead a "monster" or something evil to overcome), she came to the conclusion that if she were to murder her mother, she would be able to escape the abuse. she came to this conclusion because she had been taught by her mother that there is no other escape and that she will find her no matter what she tries to do. even if there were ways she could have escaped, her brain was so fried by the constant abuse and she had already had this learned helplessness literally beaten into her that the only option she could think to do is to eliminate the threat, to murder her mother.
i think it's entirely unfair to say that she was at fault because it completely ignores just how horrific the abuse she went through was. like, she was regularly beaten with a metal pipe, made to stay up through the night, had minimal privacy, constantly abused and berated for anything she did, her mother literally hired someone to chase after her and bring her home one of the times she tried to be independent. you cannot expect someone who has been tortured this badly for this long to think rationally or simply be able to up and run away.