Mahou Shoujo Suzune Magica

A middle-schooler who gallantly sleeps in, Suzune. Though she always goes about with a bright smile, there's another side to her. That is, she's a magical girl assassin. What will be the fate of the four magical girls she ambushes...?! The first chapter of the spinoff that asks about the existence of "magical girls," and the goodness and evil residing within oneself!

(Source: MU)