After losing his girlfriend in an accident, three years later Lee Hyeonwook tries to track down her little sister, Yoon Sena, when he finds out she's struggling.
Hyeonwook keeps finding excuses to see Sena, but there's trouble when the loan sharks are hot on her trail again. ANA is in a bad spot when the president collapses.
After temporarily accepting the position of president, Hyeonwook offers Sena a position to train as a songwriter at ANA, but PD Seo Jaeyoung wants to get rid of both of them as soon as possible.
Hyeonwook is left to pick up the pieces when Jaeyoung and the majority of Infinite Power leave ANA without Shiwoo. Sena works hard on her song despite being ostracized in the company.
Hyeonwook gets Shiwoo to stay with ANA as a solo singer, and the company must work as a team to transform his image. Sena must re-work her lyrics to match the feelings of a man instead of a woman.
Sena is let down when her song isn't used for reasons beyond her control. As Shin Haeyoon notices Hyeonwook and Sena getting closer, she becomes increasingly jealous.
As Shiwoo's song gains popularity, offers start rolling in for Sena as a songwriter. Hyeonwook is nervous as Jaeyoung starts mentioning Yoon Soeun to Sena.