The Wastrel Heir Forced to Rule

A modern office worker transmigrates into a marquis's eldest son, foreseeing his family's execution by the prime minister. He acts as a dissolute wastrel to force his father to resign. The emperor views his actions positively, interpreting his attempts to slack off as calculated moves. He is promoted, exposing the prime minister's treasonous plot. He asks to return home, but the emperor appoints him prime minister. His path to a lazy life is blocked.