Jeo Sanna spent her teenage years training to become an idol. As one of the few black girls training in Korea, she was on a path for greatness. Until an attack by overzealous fans ruined her face, and ended her career. After years out of the public eye, she's pushed back into the limelight and drama. The only bright spot in this dumpster fire is Daejun, the man that broke her heart.

Yang Daejun is the main singer of the K-pop group Tempo. For years, the group has been his family. The dominos start to fall when a group mate dies. They now must deal with the press, contract negotiations, promoting their next album, all while trying to channel their grief and anger. Then Sanna comes back. The woman he walked away from. With her return, he doesn't want to let her go again.

The new label, Sins Entertainment wants to sign Sanna and bring her in as a member of the new girl group Dynasty. Tempo is also offered a deal with Sins, but they would need to start from scratch. With a chance to rekindle a teenage love affair, Sanna and Daejun will have to deal with rumors, scandals and new roles with the label. Will they be able to come together in harmony, or will too many sour notes strike the wrong chord?