Having reached this point, I thought I'd mention something about forgiveness. Looking around, there's good psychological evidence that forgiveness is often very good for mental health, decreasing things like depression, anxiety, stress and more. Ultimately, I think the core in things like this is finding a path to closure. Finding a way to reach what you consider a satisfactory conclusion to the whole thing, so that it's truly something in your past, not something you carry with you. Pressing charges, exposing the culprit or otherwise forcing him to pay is one path. You confront the situation and the one responsible, bring about consequences, and force the culprit to a place where they can never see you. However, it's a dangerous path for many. It can backfire, especially if one can't get a conviction in court or the culprit is able to get around any attempts to get back at them. Even if a conviction is achieved, being forced to repeatedly relive the experience in front of others while being hit with skepticism and accusations can add a lot of stress.
Forgiveness is also a path though, letting go of your hate and just moving on. There's a satisfaction that can be gained by confronting the person that hurt you and saying that you don't want to hurt them back, you just want to put it all behind you. It's a different way of taking control and shutting the door. That said, this too is a very dangerous path. You have to live with the fact that the person responsible for this pain is out there, that you could meet each other without warning, and if the person isn't repentant or falls back into old habits, the whole thing could happen again to you or to others.
Really, there's no absolute answer. There are many variables depending on the victim, the exact situation, as well as the perpetrator and their own contrition or lack thereof, which together can play a big role in determining what impact any choice could have on the psyche of the victim. It's common in this day and age it seems to immediately insist that the answer is to call them out and put them in jail, and there's certainly nothing wrong with going that route. From a public security perspective this is certainly a good idea as it reduces the risk of further offenses. From an individual perspective, however, it's not as easy to judge.
My point is, forgiveness isn't reason to condemn someone. It doesn't mean the victim is okay with what happened. In fact, expressing forgiveness demonstrates that they recognize that something bad has happened and that there is reason to resent or forgive. And just because someone offers forgiveness doesn't mean they're "friends" again. Chisa in this story forgave Takigawa because she was unable to find closure otherwise. All of the negative feelings were still stuck just beneath the surface waiting for triggers to boil out again, and she decided this was the best way for her to put it behind her and move on with her life. It wasn't so they could be friends again, it was so she could forget about him entirely. It was her choice to try and heal herself, and there's nothing worth condemnation in that decision.