One Step (Hangul: 원스텝; RR: Wonseuteb) is a 2017 South Korean musical drama film directed by Juhn Jai-hong and starring Sandara Park, Han Jae-suk, Cho Dong-in and Hong Ah-reum.

Its production was inspired by the domestic Korean success of the American film, Begin Again.

The accident causes her to see sounds in color which is often disorientating, forcing Si-hyun to protect her ears.

Upon hearing Si-hyun humming a strange melody in her sleep, Ji-won's brother, Woo-hyuk (Cho Dong-in), writes it down as a score and gives it to her, hoping that it would help her remember something of her former life.

Meanwhile, Ji-il (Han Jae-suk), a failed songwriter stumbles upon this score and offers to find the melody.