Kurokishi-sama kara Zenryoku de Dekiaisareteimasu ga, Sugomori Seijo wa Kyou mo Hikikomoritai!

https://www.cmoa.jp/title/2999... After a mysterious accident robs her of her magic, Princess Lulutica of the Holy Kingdom of Philosophy is cast out to a convent as a child. Years later, she's perfectly content enjoying a quiet, secluded life—until one day, a devoted holy knight named Noah suddenly abducts her, calling her “My Lady” and pledging unwavering loyalty. With her brother, the Holy King, missing and the throne in chaos, Lulutica finds herself thrust into a deadly royal power struggle. Despite her confusion, she begins a new life in hiding with the overprotective Noah, who insists on keeping her safe at all costs. A sweet and smoldering fantasy romance between an abandoned saint and a love-starved black knight who’s just a little too intense!