Kokou no Ou to Hidamari no Hanayome ga Saikou no Fuufu ni Naru made

Wilfred, known as the "Martial Tyrant," is a king feared by his subjects. Alicia, a princess from a humble background, is married to King Wilfred in a political arrangement. Alicia is afraid of the intimidating Wilfred at first, but over time, she begins to notice his hidden, more gentle side. In return, Alicia's kind and innocent personality also touches Wilfred's heart... This is a story of a marriage of opposites, where a solitary king and a sunny princes discover love and become the happiest couple in the world!

(Source: Square Enix, translated)