Key to the Flame's Heart

Lucy tried publishing a novel but failed because her work was too amateur. She asks Levy for advice and is given the idea to write about her adventures on jobs with Natsu and everyone as characters in her story. She receives fan letters of people who read her book and gets stuck on some that state her character and Natsu's character like each other. She starts thinking about their relationship as a team and if there's something more. A Nalu fanfic