Six hundred years before the witch Bayonetta's later exploits, a young and timid girl named Cereza lives under the strict care of her stoic teacher Morgana. Born from the forbidden union of a Lumen Sage and an Umbra Witch, Cereza carries the weight of that scandal: her father was banished and her mother imprisoned as a result. Longing to prove herself and to free her mother, yet feeling underappreciated no matter how hard she trains, Cereza is drawn into the forbidden Avalon Forest by a mysterious boy who appears in her dreams. Deep within the woods she is set upon by faeries and, in desperation, performs a demon-summoning ritual, binding an unruly demon to her beloved stuffed cat. Naming the creature Cheshire, the unlikely pair reluctantly join forces to survive the enchanted forest.