A boy who's the actual macguffin, not the hero trying to find it. The show flips the standard magical girl setup by making Souta the living key everyone's hunting, which means every fight is personal in a way most shoujo adventures never reach. Akazukin and Val aren't supporting cast, they're the ones protecting him, and that reversal runs through everything the show does with its action and stakes.

Long ago, science and magic shared one world, until God, fearing what humanity might become, split it into Elde, the world of science, and Fandavale, the world of magic. When the evil witch Cendrillon returns in Fandavale, she schemes to rule both worlds and hunts for a powerful key. Souta Suzukaze, an ordinary boy from Elde, meets Akazukin, a mysterious girl from Fandavale, and Val, her talking silver wolf. He learns that the key is inside him. Akazukin, Val and the other Fairy Musketeers set out to guard him from Cendrillon and her Nightmarelians, who want the power he holds. The adventure takes Souta into the magic world, where he encounters figures such as Snow White and Hansel and Gretel in a lighthearted fantasy comedy.