Royal Fianceロイヤル・フィアンセ ; The Royal Fiance

From Shinmakoku Scanlations: Honami Kairi's fate changes when he accepted an offer from an old man to work for a rich family as a housekeeper. The low-level job suddenly transforms into a wedding workout with his schoolmate, the foreign Royal Prince Shou...! It's a fairytale with a twist...