Forgiveness is often seen as a virtue. Rising above the pain you've suffered, empathizing with the person who caused it, and releasing them from guilt is a magnanimous and kind thing to do. It can also be genuinely empowering for the person whose been hurt to let go of their resentment and anger, and let the person who hurt them know that they're doing just that.
But forgiveness also has a dark side. Sometimes, people who have endured unimaginable pain are expected to simply let it go in the name of existing peacefully with everyone else. Meanwhile, the hurt person's valid emotional needs remain unaddressed.
This is shockingly common in anime. No one ever gives Sasuke Uchiha the space he needs to feel the extremely justified rage he has at the Konoha government for forcing his brother to slaughter their whole family. Everyone applauds Tohru Honda for forgiving Akito Sohma for verbally and physically assaulting her, and Akito's family is expected to do the same, even though Akito's offenses include literally blinding someone because he wanted to get married and smacking a little girl across the room.
The Ancient Magus' Bride, an anime from the Fall 2017 season, takes a different approach to forgiveness - and it's so much better than anything you've ever seen before. After Chise Hatori's father abandoned his family, Chise's mother struggled to support herself and her daughter. It was difficult for her to make enough money as a single mother, but it was even harder because both of them were endlessly harassed by malevolent spirits. One day, Chise's mother decided that it would be be easier to live if she didn't have to care for Chise, so she attempted to choke her to death. Horrified by her actions, she let go of Chise's neck, then committed suicide instead. Chise's mother's actions are somewhat understandable - she was deeply depressed, and saw no way out of her desperate situation besides taking her daughter out of the equation. It would have been easy for The Ancient Magus' Bride to have Chise forgive her mother on the grounds that her mother was suffering. Earlier in the series, when Chise had such low self-esteem that she willingly sold herself in a slave auction, she probably would have thought that her mother should have just killed her. But when Chise actually confronts the image of her mother, she does value herself, and she can't forgive a mother who would try to kill her child for any reason.
What she can do is move on. Chise doesn't have to let the memory of what her mother did poison her present or her future, and she isn't required to be okay with it in order to let go. The moment where she decides to leave her mother in the past - without forgiving her - was one of the most powerful anime moments in recent years. But Chise's approach to forgiveness is not absolute. She does forgive when she finds it appropriate to do so. When Elias goes behind her back and tries to sacrifice a friend of Chise's in order to save her from a dragon's curse, she's furious with him, but not so furious that she has to cut him out of her life. She's willing to allow him to try and make up for it. When she discovers the tragic explanation behind Joseph's villainous behavior, she tells him what she learned the hard way from her mother - suffering doesn't give you permission to make other people suffer. She doesn't forgive him for repeatedly attacking her, but she does empathize with him and offer comfort, and she allows him to recuperate on her property once she sees that he plans to change his behavior.
The Ancient Magus' Bride embraces what's truly powerful and productive about forgiveness - giving people the chance to actually redeem themselves, while still holding the accountable for their actions. In this anime, forgiveness and redemption are possible, but they must be earned. It doesn't dismiss people as worthless monsters when they screw up, but it also doesn't let anyone get away with abuse.