Her tenth year since debut, the two-time consecutive year-end grand award winner: Baek Nokha, the undisputed representative female soloist of South Korea.

On what should have been her greatest day—a day where she was to receive another grand award—the unexpected news of her mother’s death turned it into her worst.

“Do you want to save your mom?"

A mysterious cottonball appears in front of the sorrowful Nokha. It says that if she accepts its proposal and fulfills it, it will bring her mom back to life.

“I don’t know what kind of proposal this is, but I accept.”

To return to that moment before everything changed, Nokha accepts the proposal. After making a contract with the cottonball, she opens her eyes in another person’s body.

Then…

[System]
[Congratulations!
You have become "Yoon Chung."]

[From now on, you are a member of a girl group destined to fail.]

[You must save Still Blue!]

Can Nokha, now member Yoon Chung, save the girl group from its destiny of failure?