The Courageous Warriors of the Garden of Hope have summoned Nagisa, Honoka, and Hikari to protect their kingdom from a witch who plans to steal the Diamond Line, which is a set of jewelry the queen of the Garden of Hope wears to a ceremony every year to replenish the water of the kingdom. The witch plans to resurrect the Dark Lord and if she does so, not only will the Garden of Hope be destroyed, but other kingdoms in the galaxies, including the Garden of Rainbows and the Garden of Light. Source: ANN

In the city of Minato Mirai in Yokohama, the news of Fusion's defeat by the Pretty Cures is the hottest topic in town! Girls everywhere, were in love with the Pretty Cures, are dressing up and acting as their favourite Cures. Only Sakagami Ayumi, the new transfer student, is alone by herself. On her way home from school, Ayumi encounters a strange creature. After naming it Fuu-chan, Ayumi and the creature soon become good friends. However, Fuu-chan is actually a piece of Fusion, and holds the power of darkness. In an effort to make Ayumi happy, Fuu-chan swallows up everything that Ayumi dislikes, creating chaos in school and throughout the city! To help bring across Ayumi's true feelings to Fuu-chan, all 28 Pretty Cures were gathered once more. When everyone's power comes together, a miraculous light starts to shine.