Ruri Aoki was just an average high school student until one night, she suddenly grew horns. Surprised by this change, Rumi asked her mother about it, only to learn that Rumi was actually half-dragon. Although concerned, Rumi went to school hoping her new appearance wouldn't draw attention. Unfortunately, her classmates noticed and bombarded her with inquiries. Moreover, this new ability allowed her to shoot fireballs, which was both thrilling and terrifying. To help Rumi control her power, her mother took her to the forest where her dragon father lived, hoping he could provide guidance on how to manage her abilities safely.