Jin-seong, a boy who believes his father Hyun-joong's sudden death is his fault, wants to erase the melody his father used to sing when missing his mother from his memory. Because the longing makes him more ardent. Thus, Jin-seong becomes lonely and alone. Eun-soo, a cellist, sets out to find a band to perform with. Eun-soo's hearing gradually deteriorates, and she wants to engrave in her memory the fact that she was a cellist and the beautiful moments with the loved ones who made her happy when she played the cello, and she is trying to create a melody. The band izi takes to the streets to find a vocalist. They happen to meet Eun-soo on the street and ask her to become the band's vocalist, and Eun-soo also forms a band for her special performance. As Eun-soo collapses before the concert, the members of band izi worry about her health, while Eun-soo wishes for Jin-seong to complete the unfinished score he has kept and sing it. Finally, the concert everyone has longed for begins, but Eun-soo suddenly disappears...