I think you have to take into consideration her position in the entire matter. Her teacher is someone who is highly respected among students and staff members and is seen by the entire school body as someone who cares about the students' well-being. If she had tried to out his sexual harassment to either the other teachers or the authorities, there would have been too many people supporting the teacher's case given his good reputation and would not have likely believed her (Even if they were to search for evidence, he either would have had the evidence either hidden well, disposed of before being investigated, or no physical evidence at all). Additionally, since Sachi was bullied by the other students to begin with, they would've probably called her off as being a liar and just wanting attention and it would have caused the bullying to probably escalate further. If she had tried to tell her parents, given their abusive nature, they would've had more reason to beat her as a result of being either a "liar" or "causing more problems for them" by getting the police or school staff involved. To sum it up, Sachi was in a position where she was driven into a corner and had NO ALLIES to turn to for support. If anyone were in Sachi's shoes, they would've been under just as much emotional stress and would've lost any hope in finding a way out of that situation.
Ah I upvoted by accident.
Anyway if you were the subject to sexual, psychological and physical abuse who can you even confide in? She didn’t have friends, her teacher was well respected so she can’t tell anyone. NO ONE WOULD BELIEVE HER! She grew up with the abuse, she’s mentally unstable, she grew up to believe “Ah this is how life is I can’t change it” you need to see things from her perspective before lashing out on a character that isnt in the right place mentally. You can tell something’s off about her especially through her monologues. Aiya

She really ticks me off in the fact that sje didn't tell anyone about the sexual harassment and even willingly went to the place that disgusting teacher told her to??? Like, WHY?! I just dont f understand why she would just stay quiet about all of it. She could've simply told the school and it would be over for him smhhh How I hate dumb characters