In this world, there is a front and a back. 72% of all deaths in London since ancient times are related to "alien beings" called dragons that people cannot see. However, there are also people who face dragons in unknown places. The only people who can see the existence of dragons are those who live in Reverse London, which is located on the "back" of Front London. Among them, the chosen ones become witches/wizards and have the qualifications to directly contact dragons. The protagonists are the protection officers of the natural dragon protection and management agency "Wing Bind" (commonly known as WB), the witch duo of Noelle Shinbashi and Nini Spunkel. Their mission is to protect and manage the dragons that live in London on behalf of people who cannot contact dragons.