Park Mun-su was Joseon's secret inspector and his stories are basically a K-drama

Yeongjo sent Park Mun-su as an amhaeng-eosa (secret royal inspector) to travel the countryside in disguise, investigating corrupt officials. He'd roll up to a town looking like a random traveler, gather evidence, then dramatically reveal his royal badge and arrest everyone. The stories about him became so legendary that most of them are probably fictional at this point — but the core truth is real. He actually uncovered massive corruption rings, freed wrongly imprisoned people, and punished officials who were bleeding their districts dry. Korea's Batman if Batman had a government job and a horse instead of a Batmobile.