The Pambansang Krung Krung ng Pilipinas, Sandara Park is a girl who got involved in an accident and is on her way to finding her memories with music in the film, "One Step."
Si-hyun (Sandara Park) lost her memories after she was caught in a car accident. Her amnesia caused her to see sounds in color which made her even more confused and lost. She later ecountered Ji-won (Hong Ah-reum) who moves in with her after she was discharged from the hospital.
Ji-won's brother, Woo-hyuk (Han Jae-suk), hears her humming in her sleep and writes the score down and gives it to her, hoping that it could help her remember something.
Then, everything changed when she stumbled upon a failed songwriter, Jee-il (Cho Dong) who offers to find the melody. Now watch how will she be able to find her past with music in cinemas starting May 10!