"Dunbine" is set in Byston Well, a parallel world that resembles the countryside of medieval Europe with kingdoms ruled by monarchs in castles, armies of unicorn-riding cavalry armed with swords and crossbows, and little winged creatures called Ferario, flying about offering help or hindrance depending on their mood. The main draw to the series were the insect-like "Aura Battlers", used by the population of Byston Well to fight their wars. These fighting suits are powered by a powerful energy called "aura" or "life energy." Certain people are strong enough with the aura-energy to act as power-supply to these mecha, making them Aura Warriors.