At the performing arts division of Seishou Music Academy, the ever-evolving stage threads the lives of its students together as they tirelessly hone their craft. Yet, as the girls prepare for a new rendition of the previous year's performance, the carefree Karen Aijou begins to settle for a smaller role. However, her waning passion is reignited by the return of her childhood friend Hikari Kagura, whose sudden transfer to the academy triggers a flurry of changes in the class dynamics.

Subsequently, Karen chances upon a secret battleground underneath the school, which houses a set of auditions that will crown its ultimate victor as "Top Star." As she dives headfirst into these enigmatic trials, Karen begins to learn about the tribulations that come with vying for the top. Even if fate wills them apart, Karen and Hikari must fight in hopes of fulfilling their childhood promise: to become stars together.