Tsuihou Sareta Akuyaku Reijou to Tensei Danshaku no Slow de Fushigi na Kekkon Seikatsu

Kuro Heartfield is a minor lord of the frontier territory, but his true identity is that of an ordinary 25-year-old man who was reincarnated into the world of an otome game. He has been exiled to this remote region due to the resentment of some high-ranking nobles, but he found his new life to his liking, and so he has no complaints.
Until one day, when he receives a marriage proposal that he could not refuse. His soon-to-be bride's name is Lady Violet Valentine. She is suppose to be a respectable noble lady, the daughter of a duke, but her true identity is that of the so-called villainess, the heroine's antagonist in nearly all routes of this otome game.

This is the start of a slightly mysterious married life between fellow outcasts, both hoping to find a place where they belong!

(Source: Pixiv Comic, translated)