They say that in Seoul, strange things happen under the waning moon… especially during storms. A modest college student, So Minna, works part-time as a waitress at the “Blue Dragon” diner. One day, on a rainy day, her measured life is disrupted by a handsome guest who is cute—but extremely uncooperative—and whom she accidentally spills hot coffee on. If only she knew that meeting a dragon brings more than just good luck… First, the tickets she finds near the diner invite her to meet one of the popular idols. Then, his fan suddenly disappears, and there’s a strange police officer investigating the case—one who hates lunar eclipses. All these events lead Minna to two riddles from her past: where her father disappeared, and why her ex-boyfriend left her right before graduation from middle school. And what if one day she has to choose between feelings for the wonderful dragon and her own life?