Kaburidani

Rookie police officer Shinta Satou is driven by a strong sense of justice. When he throws himself in front of a speeding van to stop it from plowing into a group of children, he wakes up to find himself thirteen years in the past, back in his high school days. But there's a cruel twist. The day he's returned to is the very day his best friend took his own life. Unable to change what happened, Satou is once again forced to hear the devastating news of his friend's death. Back then, overwhelmed by grief, he never even attended the funeral. This time, however, he goes to pay his respects, only to uncover the shocking truth that his friend had been the victim of bullying. "Why was I sent back thirteen years?" Clutching the service pistol that somehow traveled through time with him, a new resolve begins to take shape within Satou...!! (Source: Akita Shoten, translated)