Restart by Gordon Korman is a middle grade story of redemption through amnesia. The book opens with Chase coming to in a hospital room. Except he doesn't know who he is or how he got there.
Rather than tell him everything, the adults in his life (parents, teachers) decide to let him relearn through experience. Of course the idea is that it will help jog his memory. But as secrets come out, it's more likely that they are just so embarrassed by how horrible he used be and rather like Chase 2.0.
At school Chase ends up befriending the very kids he once persecuted. He ends up feeling horrible about what he did and can't believe for an instant that he would ever do those things even as he learns the facts from multiple reliable sources.
There is a second near the end of the book where Chase has to face the consequences of his actions. It comes in the form of a court case. Even there the amnesia helps him out of an otherwise bad situation because it gives him a way to show that he's reformed.
And that's where I have the most trouble with this book. Chase was a bully for most of his life, minus the few months in this book and his very early childhood. This book isn't about a bully learning or developing empathy through hard work or about his victims getting relief from his horrible actions through help from adults. Instead, it's a medical get out of jail free card.