Enredo

Go Mi-Nyu, a girl about to become a nun, is asked to cover for her indisposed twin brother, Mi-Nam, who's on the verge of becoming a k-idol. To do so, she disguises herself as a boy and joins A.N.Jell, a really popular boy band.

The management company of the idol group A.N.JELL insisted on adding a new singer to the group as the lead vocal's, Tae-Kyung's, voice was hurting. However, the new member Mi-nam, had to go to the States to repair a botched eye job just before signing the contract. His agent came up with the idea of having his twin sister, Mi-nyu, stand in for him and pretend that she was her brother. The two of them grew up in an orphanage and Mi-nyu, who was all set to become a nun, agreed to this charade as she didn't want to spoil her brother's chance of fame which would make it easier to look for their mother.

Go Mi Nyu is a girl who wants to be a nun, for she has lived in a convent since she was abandoned there with her twin brother Go Mi Nam - whose dream is to become a singer so he can meet their mother - after their father died. One day, a stranger gets in contact with Go Mi Nyu and asks her to impersonate her brother while he recovers from a surgery because he has been chosen to be a part of Korea's famous kpop boy band, A.N.JELL. It becomes a difficult task when she is taken to live with the other three guys from the band and even more difficult because the leader and vocalist, Hwang Tae Kyung is mean to her. However, when he discovers the truth about Go Mi Nyu - along with the guitarist, Shin Woo, though each of them think they're the only ones who know the secret - Tae Kyung tries to protect her, and feelings are born between him and Mi Nyu. A secret binds the fates of the two people, a truth that will test those feelings between them and can bring them apart.