All of Sato's Novels

The Bastard Called Brave And The Former Fiancé, I Will Crush All Of Them
    The continent’s largest kingdom, the Kingdom of Westphalia The boy Light who lived there had the lesson of the sword from his father who was a former knight of the kingdom, together with his childhood friend Lyrica and Sere. Both Lyrica and Light being childhood lovers, promise to be engaged with each other. Sere also being in love with Light decided to be Light’s mistress. Because you have to be a knight to have a mistress, Light slaves himself to point of death in order to be a knight of t