Iwadate Danshaku-ke no Goreijou

A girl should marry into a good family! Born into a baron's family, Iwatate Mikako has only one dream. To train as a bride, hone herself, and marry into a family with a higher nobility than the Iwatate family. Now is the time to be of use to her brother, who has sacrificed himself for the family since he was a child!! -- Soon, a big opportunity will come to Mikako, but...!?

(Source: Comic Days)