Coloris Felix Matriva, The second male lead of the Novel you read, he is the Crown prince of the Nation.

One Day you woke up as the Duke that would marry The Heroin in the future but you didn't like her at all so you decided to marry The Crown prince instead, but he loved the Heroin very much and you needed to convince him to Love you back. You had a big and hard mission before you. It seems the Novel didn't start yet

You requested a meeting, he knows you as the young Duke of Schwarzatal.