Wakeari Hakushaku-sama to Keiyaku Kekkon Shitara, Gijou (Roku-sai) no Keiyaku Haha ni Natte Shimaimashita.

Maria Martini, the daughter of a baron, enters a contract marriage with Count Ricardo Ricœur for one year only. Ricardo's previous wife had been unfaithful to him and left him, and ever since he has been repeatedly approached by women looking to honey-trap him into a remarriage. Maria's role was supposed to be acting as a cover to protect him, but during the course of their life together, Ricardo's behavior becomes stranger and stranger. The first thing that comes to mind is that Ricardo's daughter, Lydia, is very interested in her new mommy. A contractual marriage begins a too-happy married life.