Furyu Sasai

The black knight, Quill, is suddenly asked to marry the country's saint, Linetta Series. Hoping to escape the prospect of marriage, he accepts the ill-suited proposal, but she has lost her emotions as the price of her role as saint. His days with Linetta, whose emotions are unreadable and like a beautiful doll, unexpectedly stir his heart... When a knight who has given up faith meets a saint who has forgotten how to feel, their destinies begin to quietly waver. (Source: Comic Walker, translated)