Following Fusion's defeat by the Pretty Cures in Minato Mirai, Yokohama, the city buzzes with excitement over the heroes' victory. While girls around town embrace their favorite Cures, Sakagami Ayumi, a lonely transfer student, stands apart. One day, Ayumi befriends a peculiar creature she names Fu-Chan, unaware that it harbors dark powers as a fragment of Fusion. As Fu-Chan absorbs Ayumi's dislikes to please her, chaos ensues in school and the city. To convey Ayumi's true emotions to Fu-Chan, the 28 Pretty Cures reunite, unleashing a radiant light through their collective strength.