Set at the prestigious Noble Academy, 13-year-old Haruka Haruno dreams of becoming a princess, inspired by a cherished childhood picture book. Her life takes a magical turn when she transforms into Cure Flora, thanks to a "Dress Up Key" gifted by Prince Kanata of the Hope Kingdom. As she discovers her powers, she teams up with fellow students—14-year-old Minami Kaidou as Cure Mermaid and 13-year-old Kirara Amanogawa as Cure Twinkle. Together, with the help of fairies Pafu and Aroma, they battle the dark witch Dyspear, who seeks to extinguish dreams and spread despair.