Haine Otomiya, a 15-year-old high school student at the elite private Imperial Academy, was apparently sold to the Otomiya family by her father, Kazuhito Kamiya, for 50 million yen. Disoriented with her place in life, she became a gang member until she met Shizumasa Togu, who told her to live life how she wanted to. Recognizing Shizumasa as the author of a treasured picture book given to her from father, Haine reformed herself and entered the Imperial Academy to try and win his love.
However, Shizumasa is the Koutei of the school, the sole Gold rank student as the admired President of the Student Council. Through various circumstances, the Bronze-ranked Haine is tricked into becoming Shizumasa's bodyguard and assigned the special rank of Platinum - which designates her as the Koutei's companion. To Haine's surprise and disappointment, Shizumasa claims not to know her and acts coldly toward her. Still determined to win his love, she soon learns that the Koutei is not Shizumasa, but his twin brother Takanari. In the brothers' childhood, Shizumasa won the right to be recognized as the heir to the prestigious Togu family, which left Takanari to become his brother's "shadow" and was reported to have died. Because Shizumasa is sickly, Takanari is forced to assume Shizumasa's identity and reluctantly falls in love with Haine. Their relationship is strained by Haine's uncertainty as to whether she loves Shizumasa, whose kind words saved her during her darkest crisis of identity, or Takanari, who is revealed to be the author of her beloved story book.
Haine has been in love with Shizumasa Togu since she read the fairy tale he wrote as a child. However, the Emperor is so well sequestered by the student council that she hasn't been able to speak to him in the three months she's been at the academy. And as rumor has it, he already has a lover...
Haine has been introduced to the entire academy as "Platinum," the title granted to Shizumasa's (albeit fake) girlfriend. Haine must now adapt to her newfound popularity among the students, as well as get along with the jealous Maguri--the boy Shizumasa jilted in favor of her!
Haine goes to the Togu mansion to talk to Shizumasa after their quarrel, but the guards won't even allow her inside the gates! Haine gets some help from Maora to sneak into the mansion grounds, but now she'll have to get past the family's final line of defense...
Students at Imperial Academy are lining up for the "Confess Your Love" rally, during which students announce the name of the person they love to the entire student body, in hopes of winning over their beloved's heart. Maora wants to confess to Maguri, but Maguri already has plans to confess to Shizumasa!
Haine has been stripped of her Platinum status and ousted from the student council. Shizumasa refuses to acknowledge her, and she learns that even her adopted family has been lying to her. With nowhere else to turn, Haine returns to the man who sold her to save his business--her birth father, Kazuhito Kamiya.
Haine learns Shizumasa's secret and must continue to act as if nothing has changed amidst her conflicting emotions. As the members of the student council plan a school play, will Haine be able to maintain Shizumasa's deception in front of the others?
Determined to make Haine fall in love with him, Takanari tries to win her over at every opportunity. Haine is troubled by her growing feelings for Takanari, but she's even more concerned about her best friend Ushio's long list of paramours...
Haine breaks up with Takanari to be with her friend Ushio. But rather than being happy about it, Ushio starts to feel more alone than ever--and turns to an unexpected source for comfort.
Learning the truth behind her parentage and the reason she was put up for adoption, Haine reverts to her yanki ways. She rejoins her gang and comes up with a plan to break into the Kamiya mansion to abduct her mother. The only thing standing in her way--the twins!
Haine's family has been reunited, but the estranged Togu family still retains many of its secrets. Shizumasa and Takanari are increasingly at odds with each other as each one tries to win Haine's love. Will the twins ever be able to reconcile when they're both in love with the same girl?
Haine goes to Shizumasa and Takanari's grandfather, the head of the Togu family, to ask him to release the twins from their fate. He tells her she must pass the same trial the twins went through for determining the Togu heir. Haine agrees, but little does she know that a former friend is now out for her life.