Momoka Sendou (nicknamed "Dragon Girl") and Ryuga Kou are childhood friends. Momoka is a martial artist, and Ryuga is a Chinese magic master who banishes demons. In order to increase his power, Ryuga calls on the spirit of a dragon to possess him, but the spirit enters Momoka instead. Now the two must unite forces and fight demons together!A demon serpent king who appears once every hundred years to select a bride has abducted Momoka's friend Shunran. Will Momoka and Ryuga be able to defeat the demon before Shunran is lost forever?