Unmei no Koibito wa Kigentsuki

Fiona was born into a noble family, but she eschews a typical noblewoman's life in favor of working. Unfortunately, the social pressures of her status are not so easily ignored. She learns that talks are underway to arrange a marriage for her...whether she likes it or not. If Fiona gets married, she'll be expected to quit her job and give up her independent lifestyle. As she tries to figure out how to get out of this situation, she meets Giles, a nobleman who also wants to stay single. Together, they hatch a scheme to achieve their common goal of avoiding marriage: pretend to be destined lovers!

(Source: Seven Seas Entertainment)