Oji-sama Koushaku wa Koisuru Otoshigoro

Lyra, the only daughter of a local lord, dreams of building a warm and loving home with a wonderful husband. Marquis Jace, an older man, has given up on love, having had enough of romantic affairs. The two are engaged in a political marriage... Jace had only ever wanted a "wife in name only," but as he spends time with innocent Lyra, he begins to rediscover the love he had almost forgotten...!? (Source: Jive, translated)