Humanity finds itself on the brink of extinction due to the emergence of the Incubi, otherworldly monsters that capture humans to use as breeding material, and the only ones that can stand against these enemies are the Witches, magical girls given powers by supernatural beings. High schooler Renka Azuma is one such girl; her alter ego is Silver Lotus, a magical girl controlling countless insects to fight the Incubi day after day.

On a certain day, Silver Lotus rescues a fellow Witch, a novice named Azure Nova, from an Incubi attack. This meeting with this self-proclaimed fan of hers is an encounter that introduces a change to Silver Lotus's otherwise solitary daily life!?