The story follows a unambitious introverted middle school student called Saike Kuzushiro. After witnessing the death of his childhood friend, Mikan Karatachi, in a road accident. He cries out to God and after a fall, Saike wakes up in bed the previous morning, the day of the accident.

Will history repeat? Can he save Mikan? What power does he have to change the future?

Included one-shots:
Volume 3: The Negatibrain