After achieving victory in their school's final competition, Haruka and her fellow musicians have secured contracts as professional artists under the prestigious Shining Label. When an unexpected summons arrives from their alma mater's leadership offering advanced training, the group recognizes a critical opportunity to refine their craft in an increasingly saturated entertainment landscape. The program pairs each performer with an established idol mentor, though these seasoned professionals bring their own eccentricities and interpersonal friction to the dynamic. Facing expanded competition and a broader ensemble of talented individuals, the narrative weaves together romantic entanglements and musical ambitions as Haruka and the princes navigate the demands of celebrity while discovering untapped dimensions of their artistic abilities.