Satoru Fujinuma is a struggling manga artist who works at a pizza parlor; ever since he was a kid, he has been holding himself responsible for a kidnapping incident; finally, the time has come for the truth from his past to be revealed.

The year is 1988, Satoru is back in elementary school where he has a chance to change the future.

Satoru is determined to prevent Kayo from getting kidnapped before her birthday.

Satoru invites Kayo to the Science Center so she won't be alone; he suspects that he's riding the same pre-Revival rail of time, and before he knows it, X-day has arrived.

It turns out that Kayo, absent from school, has disappeared after all; Satoru is tormenting himself with the thought that he should have been able to do something more; Aya Nakanishi from the nearby elementary school has vanished too.

After confirming that the fire at Airi's home is related to his mother's death, Satoru relies on a note she left behind to make contact with Sawada, a former reporter for TV Ishikari.