This drama revolves around the original pure love story between the new high school music teacher Masaki Nitta and the student Sae Izumi who is the vice-class monitor of the class he teaches. The first half of the story tells the disappearance of the former teacher and depicts the process of the deepening relationship between Masaki and Sae. The second half tells the story of the two people who can't face their true feelings and choose to say goodbye, and meet again five years later because of a strange practice. The married Masaki and the adult Sae have become an adult affair.