After leaving her childhood friend's lavish mansion and settling into a cramped one-bedroom apartment, Jiu Seo feels as though her life is in shambles. That is, until she meets Hajun and Hayul, two neglected siblings who live downstairs. Their presence inspires Jiu, leading her to encourage Hajun to audition for an idol survival show. However, little does she know that this decision will not only alter the course of Hajun's fate but also that of everyone else involved.