The girls decide to spend the rest of their summer vacation at Magic School, where they are preparing for a summer festival. As the girls spend time with Jun and the others, hearing about something causing a lack of frozen oranges, Mirai talks with the Headmaster, stating her determination to stay with her friends. Just then, Labut appears before them, trapping them in a barrier and summoning a more powerful Don Yokubal. Using the Emerald's power, Riko and Kotoha manage to break through the barrier and help Mirai, while Labut informs them about something known as Deusmast that will bring about chaos. Despite the increased strength of the Don Yokubal, Mirai's determination encourages the Cures, and the Headmaster, to combine their strengths and defeat it.