High school student, Naoya Aizawa is having a normal day with his long time friend, Tama. But on his way to school, every person in the train station suddenly disappears - except for one girl standing on the opposite platform. Was it only he that saw the girl?

After this day, he starts having weird experiences, and that he begins to realize he has different memories, and time differences than everybody else who is supposed to have experienced the same things as him.What is the mystery behind the girl he saw on the platform? (from Crunchyroll)