This is a AU where Rengoku never died but he's badly injured. Akaza goes hunting for food until he runs into a demon who reverts people back in time. When he wakes up, he doesn't remember any of his demon memories but instead gains his human memories back. He wanders through the forest until the Demon Slayer Corp finds him. They take him back to headquarters to find out more about Akaza's situation. They wanted to kill him before Tanjiro connives them to let him live and train him as one of their own. It wasn't a good idea to keep him there but they saw that Akaza wasn't himself anymore. He was somebody else that they never before. Somebody who was human before. Which Akaza was now Hakuji now?