Even after leaving Fujisawa and arriving to Ogaki, Sakuta and Mai still had not encountered one person that had any recollection or memory of Mai Sakurajima.
Upon returning to school together, Sakuta's friend, Rio Futaba, informs them that besides her, nobody at school remembers Mai either. It is then that Sakuta learns of a theory that connects the dissipation of people’s memories of Mai to certain actions and behaviors. As he fervidly rushes to keep her memory alive, Mai sees Sakuta’s determination and reaches a decision of her own...
