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 who uses nightmares to steal the life force of humans invades the dreams of Momoka's father. Momoka and Ryuga work to banish the demon, but upon waking, Momoka's father forbids Ryuga and Momoka to ever marry!