It's a crossover between Madoka Magica and Katawa Shoujo! I can copy this straight from the board:
Lilly has the ara-ara, but Misha's got the drills... So who's better suited for the Mami role? But either way, her head's going to get chomped off.
... It's actually my favourite oekaki up-to-date. It took me 7 hours after all ä_ä