Busa Neko ni Kaerareta Kiyowa Reijou desu ga, Saikyou no Gunjin Koushaku ni Hirowarete Kizetsu Sunzen desu

Marie's life as a viscount's daughter is snatched away when her own sister curses her to become a cat...and then steals her betrothed! Forsaken, she collapses from hunger, when tender hands reach out—and on the other side is the undefeated duke with a reputation for being cruel and unfeeling?! Marie's turn from misfortune to a comfortable cat life begins here!

(Source: Yen Press)