Having set out to hunt his first dragon as a dragon slayer, Basil finds that his fate has been drastically changed thanks to the interference of a Great Dragon named Nova. With the help of her powerful magic, she creates a contract that bonds the two of them forever. Together they shall travel with the goal of changing the world so that dragons and humans may live without the need to continue fighting each other. There are plenty of people who don't share this same mindset, however, and have made it their mission to stop them no matter the cost.