From Wikipedia:
The story follows Satoru Fujinuma, a young man living in Chiba who possesses an ability known as "Revival" that sends him back in time moments before a life-threatening incident, enabling him to prevent it from happening again. When his mother is murdered by an unknown assailant in his own home, Satoru's ability sends him back eighteen years into the past and Satoru is given the opportunity to not only save his mother, but also prevent a kidnapping incident that took the lives of three of his childhood friends.
