Delusion, also known as Hongjacga, is a manhwa about a young woman named Hwa-yeon who enters a contractual marriage with a cold, powerful duke named Siegren. She agrees to act as his wife for a year in exchange for a large sum of money to save her family from debt. However, Siegren is haunted by a past trauma that causes him to suffer from delusions, often mistaking Hwa-yeon for the ghost of his dead sister. The story follows their complex relationship as Hwa-yeon navigates his erratic behavior, gradually uncovering the dark secrets of his family while trying to protect her own heart. Readers enjoy the blend of romance, psychological tension, and mystery, as well as the slow-burn development of trust and love between two damaged characters. The emotional depth, dramatic twists, and the duke’s vulnerability beneath his harsh exterior make it a compelling read for fans of angsty historical romance.