The action of the anime takes place in a parallel world. The main events occur in the city of Eridana, half of which lies within the Dragon Empire of Zeberun and the other half is located on the territory of the Lapetod Seven City Alliance. The border between the two states runs along the Oriyal River. In this world, there are special powers called "spell formulas." Essentially, these powers represent a chemical reaction that materializes using special weapons and creates a magical effect similar to casting a spell. Such special weapons are called "magic devices" and come in a wide variety of types and forms, just like any other ordinary weapon. Spell formulas are used by spellcasters to fight the so‑called Twars—an abominable type of creature that naturally can use spell formulas and poses a threat to humans. The plot focuses on two main characters, the only two employees of the agency "Ashley‑Bufh & Sorel Co." They are named respectively: Gidjina Ashly‑Baf and Guy Sorrel. Every day they face a variety of orders from all kinds of clients, which require excellent mastery of spell formulas.
