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 is kidnapped! The youth known as Onyx uses the tremendous power of the black dragon to subdue her. Onyx, who refers to Rose as "princess", seeks to make her his bride! Ryuji faces his emotional scars, unleashes the powers of a slash breath short sword, an S Class Lost Precious left to him by his parents, and goes after Onyx to save Rose. However, an insurmountable wall exists between humans and dragons. Emotions clash as the battle begins! Rose is kidnapped! Onyx, the youth in black, uses the tremendous power of the black dragon to subdue her. Ryuji faces his emotional scars and decides to fight. Emotions clash as the battle begins!

Ryuji heads to the beach with Rose and Misaki. Their swimsuits starts his heart pounding! However, a silver haired girl arrives with a dangerous request. The target is a powerful breaker looking for Rose!

Ryuji gets close to George and finds the Lost Precious they are looking for. However, taking the Lost Precious Maruga has asked for seems nearly impossible. Eriko believes her plan to keep George occupied at the beach with Maruga's swimsuit has succeeded when a sudden incident ruins her plan. On top of that, Maruga reveals a secret about the Lost Precious. What is the sad past kept quiet by the white dragons? Can Ryuji and Rose conquer that sadness? Ryuji plans to steal the Lost Precious. Their secret weapon against George is Maruga in a swimsuit! However, a sudden incident ruins their plan. Maruga reveals a sad secret about the sword...

Ryuji, Eriko and Rose were attending a party with many A class and above Lost Preciouses. They also meet a new collector who seems interested in Eriko; he tells her that if he finds out anything about her other earing then he will contact her. The guests were attacked by "Odd Eye", a half-beast Lost Precious thief that Ryuji had just seen in a magazine. Later at their home, she tried to steal Eriko's earring, but end up tied to Ryuji by a failed capture device. While waiting for the bind to vanish, they learn that her true name is Ai, and try to figure out who is making her steal, and why. The next day Eriko answers a knock on the door and it is the new collector who says he has found the other earing. He opens the box supposedly containing the earing and sleeping powder comes out of it, putting Eriko and Rose to sleep. He then tells Ai to follow him, putting Ryuji to sleep as well.

The rope finally came off of Ryuji and Ai. Ai's master puts him in a closed room to ask him of his A-Class precious later. He and Ai then go to a room where he tells Ai to rest for a while, it is also revealed here that her master does actually have the other earing. Ai's master leaves the room to go get some drinks and Ai, dazzled by the beauty of the earings, puts them on. The earrings give the person wearing them the ability to hear a person's true thoughts. Ai's master comes back not knowing that she put on the earrings answers all of Ai's questions falsely, including unintentionally "telling" her that he kidnapped her 15 years ago and raised her to be a dog of his experiments. Knowing this Ai flees the room to save Ryuji. They escape to the balcony where Eriko and Rose come just in time to help. It is revealed that Ai's master is Furumori, a person being looked for by the society, and he has five lost preciouses inside of his body. After having four out of five of these lost preciouses destroyed by Rose's dragon fire, Furumori uses his last lost precious to dissapear into the atmosphere. Ai goes back to her human family where she was kidnapped from.

Ryuji wakes up finding Rose dressed up in his school's girl uniform saying she wants to go to school too. Ryuji agrees but makes her promise that she wont use her wings and fire. When they get to school, class is suddenly disrupted by by Bianca Alexandra Lou, a women sent by the society to evaluate Ryuji. She fires a SMAW at Ryuji and finds his physical level is 326 and his lost precious level is 120 . She seems slightly disappointed and says she will test his maximum lost precious level later. After a whole bunch of questioning, Bianca takes Ryuji outside to start the test. Ryuji needs to battle a Neogolem. After Ryuji severely hurts it and the Neogolem still doesn't shut down, Bianca realizes that there's something wrong with it and tries to automatically shut it down when it doesn't work, she climbs up the robot trying to shut it down manually. Ryuji and Rose engage and stop the Neogolem. At the same time all this happens, Eto figures out it's Ryuji's birthday the day after and tries to figure out what to get him for his birthday present.

All the girls get sucked into a Cursed Precious that judges whether women tell the truth or not.

A new blue dragon named Sapphie appears and claims to be the lover of Onyx and tries to take revenge on Ryuji. However it turns out that she is not too battle oriented and is forced to retreat. Misaki learns about Rose being a dragon and over in Maruga, the white dragon's home a break in by Onyx occurs. Sapphie later meets up with Rose and they become friends. She teaches her of the Dragon's coming of age ritual, namely a kiss on the dragon mark. Rose and Ryuji perform the rite only to have Rose become extremely conscious of Ryuji's presence (with the mere touch or sight of Ryuji sending waves of heat through her body) which in turn makes Ryuji conscious of her. The couple end up shy and embarrassed around each other to an extreme.

Rose's change in attitude continues even after a night's sleep. This in turn, much to Eriko's dismay, makes the couple awkward around each other. At school Rose tries to consult Misaki and Ryuji vaguely tries the same with Masato but to no avail. Rose's condition gets worse during PE, to the point where she collapses. She is transferred to the Society's Dragon Lab. Meanwhile Eriko and Bianca manage to capture Sapphie who had rerturned to regain her shoes that she had left behind. Questioning her reveals that Rose's condition is not normal and Sapphie herself does not understand what's going on. Onyx contacts Ryuji and reveals to him that the Dragon's Rite of Adult does not take effect with humans but only with dragon partners and that Rose's current condition is because Ryuji is not human but a Lost Precious with power over dragons called the "Dragon Crisis". If Ryuji continues to stay near Rose her condition will only worsen. Left with no choice, Ryuji hands Rose over to Onyx. More than two weeks later, Ryuji goes to and acts normal in school but Misaki realizes that Ryuji is hiding his own feelings. Later that night Maruga return to talk with Ryuji.

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.