Tsubomi Hanasaki is a second-year middle school student with a passion for flowers and plants. One day, she dreams of a mysterious flowering tree that withers, causing the sprites to vanish. Upon transferring to Myodou Academy, the sprites from her dream appear before her. They beg Tsubomi to become a Pretty Cure to protect the Great Tree, but she declines. However, a sudden attack by a mysterious enemy occurs, and the Heart Seed of her new classmate, Erika Kurumi, is stolen. To save Erika's heart, she has no choice but to become a Pretty Cure and fight.