High school student Ryuji's older cousin Eriko returns from abroad to drag him to the scene of an underground transaction where he gets caught up in a shoot out and car chase! While they thought they had stolen a miraculous Lost Precious from the criminal brokers, they ended up with a mysterious young girl! The young girl happily latches on to Ryuji even though they have never met! Who is this little girl? Thus begins the story of the beautiful young Rose and Ryuji!

Rose, Ryuji and Eriko are suddenly invited to the Japanese branch of the society by a researcher named Tokura. While Rosa is indistinguishable from a young girl, the society performs a variety of examinations after hearing she is a dragon, and the results are...! Unconcerned by her situation, Rose is simply happy to be with Ryuji, and enjoys eating ice cream. However, a young man in black and an underground broker come for Rose!

Rose wakes up with no memories about her life with Ryuji and her friends. Not willing to take any chances, Onyx decides to leave Japan with her as soon as possible. Meanwhile, thanks to Maruga's counseling, Ryuji finally comes to terms with his feelings for Rose and together with all his friends, he sets to Haneda Airport to rescue her.