Magical Girl Dandelion, Volume 1 by Kaeru Mizuho

A fiend who slays his own kind. A magical girl who refuses the script. A tale of light and shadow intertwined.

Tanpopo Ohanami’s quiet days are interrupted by a life-changing offer to become a magical girl! But she has one big, bad, serrated-toothed secret: Her best friend, Shade, is a fiend in a world where fiends are villains to humankind.

Shade is none too pleased with the idea of Tanpopo joining the ranks, but there’s more than their friendship at stake when Tanpopo’s grandpa falls victim to fiendhood!