Taishou Kazoku-sama to Kekkon shite Yonaoshi Shimasu!

It's the late Taisho era, and the main character, Suzu, works as a waitress at a cafe for the general public. The kind-hearted Suzu endures the harsh treatment of her employer so that she can take care of the poor orphaned children who live in the shadows of the glamorous town. Her dream is to earn enough funds to build a free diner where the children can eat until they're full. One fateful day, a breathtakingly handsome noble comes to the cafe and hits her with a life-changing proposal...! (Source: MangaPlaza)