Yomeiri no Susume ~Taisho Onzoushi no Gouin na Kyuukon~

It's the Taisho era, and Ranko Hanamiya, a former noblewoman, is now 24 years old and works as a waitress at a high-class café called Cassiopeia. Her family complains that she's too old for the job and that it's embarrassing, but she doesn't care. One day, while at work, she suddenly receives a gift from a handsome stranger, a young university student. Her co-workers are all in a frenzy, but Ranko, who has no idea what's going on, keeps her cool. At home, however, a terrible problem is brewing. Viscount Chounabashi's family wants to marry Ranko. In fact, their grandfathers have promised to marry their grandchildren to each other. Ranko, who enjoys her work and is not interested in marriage yet, refuses. But her parents, who want to keep up appearances, push her to visit the Chounabashi family for a matchmaking date. And the man waiting for her there turns out to be the unsociable young man who gave her the gift at the café, Ichirou!? (Source: Shogakukan, translated)