And this is why Yanderes are hated, because protagonists consistently fuck up at handling them correctly and people misunderstand them / their actions.
She just went and fixed his mom's attitude. The mom was gonna throw him at Gen's dads mercy just like she is, even though her problem was solved years ago. The mom DID want Rei to work so she could have it easier, but here teacher's changing the moms tune cuz she's getting called out on it by teacher. Teacher is twisting the moms arm to let her son free of the hell of that town, and offering to bankroll it. Do you see literally anyone else trying to get him out? Or trying to free him of these manipulative filth? Nah. Teach was even gonna cut the relationship off at end of high school and send him off with money. But nah, she's somehow the worst.
And teacher was right, the mom could've stopped the night visits years ago. It's clear she doesn't want to. Not like Reis dad is gonna suddenly come back and start beating him again if the mom stops fucking Gen's dad.
Everyone's tried to trap Rei in the town and the only one offering him free money and a way out is the teacher and shes hated by y'all? Y'all crazy. The rest of the cast are actively gas lighting, lying, locking him down to that town, and/or contributing to the suicide situation.