"Stella Glow" takes place in a world with song-driven magic. This song magic brought prosperity to the world, but in turn, this prosperity also brought problems and war to the world. God then took song magic away from the people. Thousands of years later, song magic reappeared in the hands of five witches. One of these witches is Hilda, who wishes to crystallize the world and leads the Harbingers. Opposing her are the Regnant Knights and the four other witches.