Si-hyun loses all her memory after a car accident and lives with Ji-won at her place, her only friend whom she met at the hospital. Si-hyun only knows that she has colored hearing in which she can see sounds in colors, and that she hears an uncertain melody in her dream every night. Weary of fainting at the slightest noise, she always wears a set of headphones as big as her face. Then one day, Ji-won’s younger brother Woo-hyuk, who is secretly in love with Si-hyun, hears her sing an unfamiliar melody in
her sleep. He writes down the melody on a score and gives it to Si-hyun as a gift. Meanwhile, Jee-il, a washed-up composer chances upon this score and offers Si-hyun to find the melody in her dreams. As the song nears completion, Si-hyun’s fragmented memories return to her.