Daimadoushi to Yobareta Koushaku Reijou ~Sekai ga Kitanainode Souji shite ita Dakenandesukedo......~ @COMIC

https://www.cmoa.jp/title/326898/

The Kingdom Cleansing Project Begins♪
Broom is My Friend! Sweep, Sweep, Sweep and Sweep, and Eventually Become a Great Sorceress—The Heroic Tale of a Cleaning Lady!

Another world polluted by a black mist. A neat-freak woman in her late twenties is reincarnated as Scarlett Northmark, the daughter of a marquis of the Vander Kingdom.
Knowing that only she can see the "mist" that plagues the world, she decides, "I have no choice but to clean it up!" and picks up... a broom! Curious and carefree, she sweeps and sweeps and sweeps as if it were a game—but one day, for some reason, she becomes able to use extraordinary magic...!?
Broom is My Friend! The heroic tale of a cleaning lady, where a tomboy princess sweeps up the dirt throughout the kingdom and becomes a great sorceress!