Eun Dan-oh is a student at a prestigious academy. One day, by chance, she discovers that she and everyone else in her world are actually characters in a comic book entitled Secret. She has a heart condition and worse yet, Dan-oh is only a minor character in this story and is expected to die soon. Not satisfied with this fate, Dan-oh decides to forge her own destiny by changing the story's plot and finding her own true love. Her hopes of freeing herself from the Writer's control becomes stronger than before when she unexpectedly meets nameless Student Number 13. But as the events around Dan-oh and Number 13 gradually starts to have parallels with the Writer's previous work, Trumpet Creeper, changing her destiny could have a price to pay.