Kyungsoo suffers from insomnia because of his struggle in the job market. One night, he goes for a walk in the park, and is captivated by Siyeon’s beautiful singing. At first, he doesn’t even know the title of the song that she’s been singing, but soon finds out from her that it’s a haunted song. Still, he longs to hear the song to soothe his insomnia, and secretly records it···.