Colette, an apprentice to the beautiful alchemist Priscilla, lives a peaceful life with her mistress in the countryside. As an aspiring alchemist, Colette spends her days training rigorously, aiming to one day become as capable as her mistress.
One day, however, Priscilla is suddenly visited by a stranger and has to leave on a journey soon after for unexplained reasons. Before she leaves, Priscilla hands her workshop in the capital over to Colette, and tells her to "help everyone who needs you".
Now on her own for the first time in her life, Colette follows the instructions of her mistress and begins to help people in need as part of her training to become a full-fledged alchemist. The path ahead will lead her onto a most peculiar journey with people from all walks of life, and behind all of these lies a sinister figure who intends to take the whole world into its grasp...