What Did I Do Yesterday? is a captivating Japanese web novel that follows the story of a civilian who, after a night of drunken revelry with his beloved knight leader, finds himself utterly infatuated with him. This tale delves into themes of comedy, gender bending, slice of life, and yaoi, offering a unique blend of genres that will keep readers engaged. With elements of assassins, kingdoms, nobles, and strong love interests, this novel explores the complexities of different social statuses and obsessive love in a compelling narrative.