Raki Kiseki is a 12th-grade student who enrolls at Star Harmony Academy with the goal of becoming an idol. Upon receiving an Aikatsu Pass from her older sister, who works as an engineer for the brand, she experiences something strange. As she opens doors that appear before her, she encounters various Aikatsu idols she had never previously met, including Yume Nijino from Aikatsu Stars! Inspired by this encounter, Raki pledges to create her own premium dress and perform it on stage.