Go! Princess PreCure.

Go! Princess PreCure is set in a boarding junior high school, named Noble Academy. The protagonist Haruka Haruno is a 13-year-old first-year student. Her big dream is to be a princess someday because she admired a princess in the picture book she has kept since her childhood. One day, she transforms into Cure Flora with the "Dress Up Key" which Prince Kanata of Hope Kingdom gave her as a good luck charm when she was little. Then she also finds other Pretty Cure girls in her school, 14-year-old Minami Kaidou as Cure Mermaid and 13-year-old Kirara Amanogawa as Cure Twinkle. As the Princess Pretty Cure team, with two fairies Pafu and Aroma, they fight against the dark witch Dyspear, who hates all the dreams in the world and wants to turn them to despair.