Natsume Wants to Be Trained [Natsume Wants Book 1] (manga)

Natsume has a problem that’s keeping him single and alone: He’s lousy in bed! Frustrated by his inability to keep a lover, he comes up with a plan - become a master of sex and shove his newfound bedroom prowess right in his ex’s face! The first step? Hiring a male escort to help him improve his skills. But when the escort, Kou, arrives at his home, Natsume is stunned to find that this man is no stranger. In fact, he’s Natsume’s own housekeeper!