My Angelic Husband is actually a Devil in Disguise

Setia accepts the marriage contract offer from Miere Lunaria, a rich but dim-witted bachelor, only because she needs the money to get out of her family's debt. Only a month into their marriage, Miere goes missing and is presumed dead. Three years later, Setia is shocked when her "dead" husband returns as a hero. Their marriage contract is about to expire, but Miere has no intention of letting Setia go. You see. there's more to Miere than meets the eye... and he's not the half-wit that everyone thinks he is.

(Source: Pocket Comics)

Note: First released in English, with the initial eligible release in Japanese followed by Korean, making it a manga by our standards.