Lumi, an apprentice aspiring to become a perfumer, is attacked by black mist on her way home. Guided by a black cat claiming to be a messenger of the Flower Star, she awakens the power of an antique flower key left by her ancestors and transforms into a Flower Fairy. Because the Seven-Colored Flower has withered due to dark magic, its seven petals are scattered throughout Flower City, causing strange phenomena that erode people's minds. For the safety of Flower City, Lumi, as a descendant of the Flower Fairy bloodline, shoulders the mission of purifying and collecting the seven petals, using floral magic to dispel the darkness in people's hearts, embarking on a magical girl's journey of growth. However, during this adventure, Lumi is attacked by another mysterious Flower Fairy, and the black cat beside her has an unexpected identity...