Higurashi when they cry. Atonement arc. Vol 16
(Graphic Novel)

"Rena has taken extreme measures to protect her and her father's happiness, but such drastic actions have terrible consequences. When her friends learn of her crimes, they feel no revulsion toward Rena, but rather a sense of regret that they hadn't been able to help her and avert this tragedy. But even if they had sensed Rena's desperation, would her classmates' pity have transformed itself from sentiment into action? Hadn't they had the same opportunity to prevent tragedy a year earlier, when Satoshi Hojo was suffering abuse at home, and failed to prevent his desperate act of murdering his aunt? How much can Rena afford to trust in a place like Hinamizawa?" -- from publisher's web site.

OT, older teen.