Set in the chaotic Sengoku period of Japan, the manga follows the life of Ukita Naoie, a feudal lord later branded as one of the era's three great villains for his ruthlessness and cunning. Born into a minor warrior family struggling to survive, Naoie rises through a relentless combination of assassination, betrayal, and political maneuvering. The story opens with his early years as a young clan head, where his willingness to use any means necessary sets him apart from more traditional samurai. He systematically eliminates rivals through poison, ambushes, and even what is depicted as Japan's first sniper assassination, all while maintaining a deceptively mild public face. His wife and parents are drawn into his schemes, often playing key roles in his plots. As his reputation grows, he catches the attention of his nominal overlord, Uragami Munekage, who becomes suspicious and reports Naoie to the mighty Mori clan. The manga then follows Naoie's struggle against the overwhelming power of the Mori, forcing him to innovate further with his assassination tactics and to navigate the shifting alliances of central Japan. Throughout, the tone remains comedic, with exaggerated expressions, slapstick violence, and anachronistic humor, even as the body count rises. The narrative focuses on how a man with limited resources and a notorious name carved out a domain in one of the most violent periods of Japanese history, using deception and murder as his primary tools.