Kiraware Maou ga Botsuraku Reijou to Koi ni Ochite Nani ga Warui!

This is the story of a detestable Demon Lord and his wonderful new wife, a destitute damsel! Our Demon Lord, Anima, is the strongest in all the world, feared by the denizens of the realm. He's forced to spend his days in solitude until, completely out of the blue, he gets summoned to another world! The one who summons him is none other than Luina, an exceedingly poor girl who runs an orphanage. The two of them quickly fall in love, with Anima swearing to use his power to protect his newfound family!
(Source: Sol Press)