Raki Kiseki is a second-year middle school student who transfers to Star Harmony Academy to become an idol. However, when she uses an Aikatsu Pass she received from her elder sister Saya, an Aikatsu engineer, something mysterious happens. Many doors appeared before her, and when she opens them, she meets Aikatsu idols she never knew before, such as Ichigo Hoshimiya, Akari Oozora and Yume Nijino. Raki vows to design her own premium rare dress and perform in it on stage.