MachiMaho: I Messed Up and Made the Wrong Person into a Magical Girl! #1

A sprite from the magical race called Mika descends upon Earth to select a champion to oppose the pending invasion of the demonic Atasunmo. But the demons invade sooner than anticipated, forcing Myu to select the first teen girl he sees: a violent, foul-mouthed, chain-smoking juvenile delinquent named Majiba Kayo.